Hey guys, recently bought a Datsun 280z project car that will weigh around 2800 when finished. I have most of the combo figured out, but wondered about which tranny I should run between a TH350 or TH400.

So, same converter flash/stall speed of 2500-3000 RPM, 2800lbs car, 454 BBC.... TH350 or TH400?

I want to hear your opinions though and why.

Thanks guys!!

Its not the case, most will disagree with me, BUT it wouldnt take more then a look to Super Stock, Stock eliminator, or Comp Eliminator to find your answer.

Cable, there is more going on here than you might realize about why the 'glide has such a drag race following - especially with a big block. There are even cases where a 'glide is better in a middleweight (low 3,000 lb range).

Points for a 'glide:
1) One LESS shift means greater consistency for the bracket/super/pro class racer.
2) Greater efficiency means that more of the engine's power is put to the ground.
3) No abrupt changing of rotational direction of heavy internal components on the 1-2 shift (see #2 above).
4) In of itself it is very lightweight and has fewer internal parts to go wrong.
5) High powered cars actually like to have the steeper/lower numerical first gear ratio. The greater load of the 'glide gearing makes it less likely that the rpm acceleration of the engine will exceed traction. This is a "dumb" traction control at its best.


In favor of the TH400
1) Legendary reliability.
2) Super widespread parts availibility.
3) Just about ANY trans guy can build one to take a pounding.

There is much more that can be said one vs the other.

Thomas

Honestly I was set to go with a TH400 core I already have, but then I remembered someone saying something about running a TH350 instead due to less power to turn.


-------------------------------------------------

Its a '75 280z that I going to shoe-horn the BBC 454 into to terrorize the local imports at the track. The car itself right now with the stock EFI 2.8 litre I-6/4 speed manual combo doesn't weigh much more than 2500 lbs.

Soon it will have a 10 point roll cage installed, then the weight of a BBC (w/iron heads). I am sure with the added weight and a few other goodies the car will weigh around 2800-3000 lbs. To save alittle more weight and help with balance, the heater and A/C stuff is removed, swapped out the stock gas tank w/a fuel cell, stock brass-copper radiator replaced with aluminum Howe, battery moved to the rear, spare tire well cut-out, and the stock steel 3-piece front valance will be swapped out for a 1-piece 'glass unit.


The rest of the body will remain stock style, including the hood (except added cowl).

Cable,

I am not trying to pee on your barbecue :eek: , you are going to have a miserable time getting that Z to hook up with the monster motor in front and stock suspension. Guy had one with a small-block and a 4-link rear, he swapped in a 500 CU and he fought for months and lots of dollars to finally get it to hook up consistent.

Originally posted by tpshea:
Cable,

I am not trying to pee on your barbecue :eek: , you are going to have a miserable time getting that Z to hook up with the monster motor in front and stock suspension. Guy had one with a small-block and a 4-link rear, he swapped in a 500 CU and he fought for months and lots of dollars to finally get it to hook up consistent. No worries Tim. Its not as bad as you might think if you set the motor back far enough.

I already have a buddy running 10.4's with slicks with his 240z. That's with a IRON headed 454.

Believe it or not, but a Z with a BBC with iron heads, aluminum intake/water pump/radiator, mini starter, etc weighes only about 300 lbs more than the stock 2.8 litre straight 6 cylinder w/aluminum head, stock brass-copper Z radiator, stock starter, etc.

The key is setting the motor far enough back to get the best or closest 50/50 balance possible. Plus, I am going to be running a 26x10.5x15 Hoosier QT slick. I am keeping the stock IRS (adding posi later), which hooks great with current 383 stroker.

In any case, I am building this as more of a toy, if it hooks..great, if not it will still be alot of fun.

Originally posted by bluerebl:


The rest of the body will remain stock style, including the hood (no cutting). I might even run single exhaust with really quiet mufflers to remain more "undercover". dual fart cans??? tongue.gif

Originally posted by young gun '71:
dual fart cans??? tongue.gif I'll only go so far, although I was thinking maybe a polished stainless muffler like Summit sells.

Use the glide. My old Vette was faster with one at about the same weight and a streetable 402.

How far back? This would be a killer car if it hooks good!

Originally posted by tpshea:
How far back? This would be a killer car if it hooks good! Enough that I might select alittle of the firewall to clear the dist.

Hopefully it will be enough.

How are you balancing it? How do you know where "50/50" is? Just curious. I know you have a friend that already has a Z with a BB, just curious as to how you come to get all the answers....trai and error? Yank the motor every so often and move it's placement?

Originally posted by LXS:
How are you balancing it? How do you know where "50/50" is? Just curious. I know you have a friend that already has a Z with a BB, just curious as to how you come to get all the answers....trai and error? Yank the motor every so often and move it's placement? I am not saying it will be a 50/50 perfect balance, I said I we'll move the motor far back as possible to get the best 50/50 balance.

How do I get all the answers? Because I am THAT good. :D

Seriously, my buddy has a 454 in a Z car that we have been mocking up with another 454/TH350, then breaking out the 4 corner scales.

I am not saying that the BBC is lighter on the front end of the Z VS a SBC. However I have seen ALOT of SBC V8 (and some BBC's too) swaps where the motor is sitting way out front with the dist sitting around 6-8" from the firewall. That means the 50/50 balance could be better, much better. We figured if we could place the motor farther back we could improve the 50/50 balance of the car...so far we have been correct. I guess I'll know soon if it works better as a drag car or a smoke show car after the mods are complete on the real car.

In any case, it will be a fun car regardless.

BBC in a Z car..=
Glide.

For traction and fitment reasons.

Glide will fit more easily, and you just absolutely will not need the additional gear advantage that a 3 speed provides with a 427 in a Z-car.

In a Chevelle, Camaro, or just about any street car, the 3 speeds are WAY better IMO, even for bracket racing, but in someting that light, that short, with BBC torque the Glide would be more than adequate.

Sounds like a fun project. Good luck.

Sweeeeeeeeeet graemlins/thumbsup.gif ...Sounds like fun, I'd like to do something similar like you, just no $$$ and too many projects. I've got a friend who's putting in a SB in a 240Z. He's almost done, just needs a lot of little things, then it's off to the track. :D

Originally posted by bluerebl:
How do I get all the answers? Because I am THAT good. :D LOL graemlins/thumbsup.gif

Has anyone run a glide in a heavy (3700) lb big block car and gone faster (or slower)? I'm considering switching to a glide, but general opinions have the car running the same or slowing a little in the 1/4

It's all in the combo. I have seen some pretty heavy cars run well after going to a Glide, but they were torque monsters.

I checked out your site, a lot of good stuff there. What would you consider the maximum horsepower is for the stock glide 1.76 gearset? I've heard they will handle 850 HP, but this sounds kind of high.

Rigrock, There was a red '70 Chevelle built by a man at Lunati Cams a few years ago and it was equiped with an 842 H.P. 540 cu.in. Big Block and had a glide and 4.10 gears. He said they couldn't get the car, which weighed 3720 lbs. with driver to run faster than 9.80 then went to a Turbo 400 and ran some 9.6s. Maybe with a traction problem the glide might work better.

TTT

the only cars i've ever seen go faster with a glide were traction hampered, small tired cars on nitrous or some other power adder. i'd say your's will fall under traction hampered dept. ;)

Originally posted by m71:
the only cars i've ever seen go faster with a glide were traction hampered, small tired cars on nitrous or some other power adder. i'd say your's will fall under traction hampered dept. ;) I agree about the traction hampered dept.

Oh, I am building a 454 afterall. So, I guess I am going to be having even more traction problems.....its going to be wild.

Here's the basic combo, the * indicates item(s) that I haven't bought yet.

Bottom End:

-454, 4 Bolt Block w/ARP Main Studs
-Bored to 4.280" (0.030" overbore), Honed w/Torque plate
-Stock 454, 4.00" Stroke Crankshaft
-Stock Big Block Chevy I-Beam 'TRUCK' Rods w/3/8" ARP Wave-Loc Bolts
-TRW/Speed-Pro L2465F Forged Pistons (25.7cc dome volume) 10.0:1 Compression w/119cc Heads
-Plasma-Moly Rings
-Clevite 77 Main/Rod/Cam Bearings


Up Top:

-Pro Topline Iron 290cc BBC Heads, 2.19/1.88" SS valves, 119cc Chambers, Exhaust ports and chambers de-burred and mirror polished
-Crane Cams .620" lift Valve Springs
-Comp Cams 7* Chrome-Moly Retainers w/matching locks
-*Lunati Solid Flat Tappet Cam: .586/.600", 276/284 adv dur, 243/251 dur@0.050", ground on a 114 LSA and 4* advance built in (UltraDyne Design Specs)
-Oil Pin Solid Lifters
-*3/8's One-Piece Chrome-Moly Welded-Tip Racing Pushrods
-*1.72:1 Comp Magnum Roller Rockers
-*Victor Jr. or Professional-Products 'Hurricane' Single Plane Intake
-*750 cfm Holley Double Pumper Carb
-*MSD Billet Distributor
-Holley Firewall Mounted 55k volt Coil
-Crane Fireball HI-6 Ignition


Suspension/Tranny/Exhaust:

-Built TH350 Tranny w/Trans-Go Shift Kit
-Nissan/Nismo R230 VLSD w/3.69:1 gear ratio
-*10" 3000-3500 Stall Converter from ATI, Coan, Trans-Specialities, or GER
-*The car will have at least a 8 point roll bar installed
-*Fuel Cell in a can
-*Front adjustable coilover springs w/custom made 90/10 drag racing struts
-26x10.5x15 Hoosier QT DOT Slicks
-1 7/8" Shorty Headers
-Dual 2.5" Exhaust, w/Dynomax bullets and polished stainless-steel mufflers exiting under the roll pan

I have done some mockups and I will still be able to reuse the JTR SBC swap motor mount spacers and setback plates. The 454 will sit in exactly the same spot in relation to the firewall as the 383 SBC. The front of the motor will be approx 2" longer than the SBC, which actaully helps things like crossmember to damper clearence. Though it is true that a BBC weighes more than a SBC, it isn't by too much. Plus the increased power will easily offset the weight gain. I should make around 550-600HP around 6000 RPM and 550TQ around 3500 RPM on 91 octane gas. I know the motor will be good for mid 10's, traction permitting of course.

I just scored a posi (vlsd) rear for the car, its still IRS though. My current gear ratio is 3.54, the new diff has 3.69 gears and is much stronger.

The diff is from a Nissan Skyline (sold in Japan only). Its called a R230. The ring gear is 9" alone. Its a viscous limited slip, no side or spider gears, just a ring and pinion.

The CV's and axles will be custom Moser pieces.

Trust me when I say, the rear is the last thing I am worried about.

Pics:

http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_23_full.jpg


http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_25_full.jpg

Pics of the finished short block, thought you guys would like to see:

http://www.chevelles.com/showroom/bluerebl/454Painted.jpg


http://www.chevelles.com/showroom/bluerebl/4544bolt.jpg

BBC in a 280Z


sick,very sick indeed graemlins/thumbsup.gif

Originally posted by mr 4 speed:
BBC in a 280Z


sick,very sick indeed graemlins/thumbsup.gif Glad you like it Chris, the car suprised alot of people with the mild 383. I can't wait to see what happens with the 454.

The only concern I have right now as far as shoehorning the 454 is headers. However, I am fairly sure Sanderson's BBC 'Shorty' headers intended for a '62-'67 Chevy II/Nova will work.

We already did a mockup and my small cap distributor is less than an inch from the firewall. It sits THAT far back. We even broke out the 4 corner scales, did some rough calc's and the balance is still pretty damn good (about 55/45). Of course aluminum heads would help, but the funds won't allow that.

Boy do I sure wish you were my neighbor!!!! Ever think about moving to LA??? tongue.gif :D

Originally posted by LXS:
Boy do I sure wish you were my neighbor!!!! Ever think about moving to LA??? tongue.gif :D Nope, hopefully Las Vegas though.

Is that the crank/rods/pistons I sold you?

Originally posted by Epistuff:
Is that the crank/rods/pistons I sold you? Nope, different motor. I gave the set to my father for his B-Day and he is working on a 454 for his '59 Chevy truck.

I honestly wish I had waited, I'd kinda like that rotating assembly more than this one.

Oh well.

Funnest car I ever owned was a 73 260z with a bone stock 350 with a built powerglide. Loved stoplight racing with the 5.0 Mustangs. They never knew what hit em. Little did they know that if we were racing more than a block, they would catch me. 14 inch tire, 3:55 gear and 4800 rpm wont last much farther. Never asked to lift the hood, just a thumbs up as they slinked away.

More pics......

This was posted when I was still trying to confirm the pan's I.D. . Anyway, its a '66-'72 Corvette pan, 5 quarts, built-in baffles, trap door, screen/pickup bowl, etc. Pretty fancy stuff for a pan designed in the early '60's.

http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_56_full.jpg

http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_57_full.jpg

http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_58_full.jpg

......and here are the headers I plan on using, they aren't Sanderson's.

http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_64_full.jpg


Driver Side Header:
http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_63_full.jpg


Passenger Side Header:
http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_65_full.jpg

I don't know who made the headers actually. I do know they were made with top quality part and good welding. The flanges are nice and thick, welds are smooth and deep, and the bends are top-notch. According to my measurements, they'll fit. Soon I'll do a mockup with another 454 and some junk heads and see where I am at.

My father has had them for years. He bought them from a speed-shop (Super-Shops) that was going out of business in Bakersfield about 8 years ago. He wanted them for his '59 Chevy truck that he was swapping a 396 into. Then we decided to swap out the front end with a '70's Camaro sub-frame so he'd have all the modern disc brakes, suspension, etc.

So being that we went with the Camaro clip, these headers wouldn't work with any car/truck with the crossmember directly under the engine.

With a little Z that's not a problem.

Long story short, I was in Bakersfield on Friday and I remembered to ask him about the headers. He just handed them over with the agreement that if I couldn't use them, give them back.

If they work, they'll save me $350+

I am going to bead-blast them so they are clean and semi-rough to the touch. That way the high-temp paint will have something to hold on to when I spray them.

bluerebl,

After you blew that 383 I was sure to see another in its place. That car will be wild. I wish you were my neighbor as well. Very cool stuff.

Keep us posted.

That'll work! ;) And yes, please keep us posted!

Here are some pics of the Pro Topline heads I took as part of trade:

http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_59_full.jpg

http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_60_full.jpg

http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_61_full.jpg

http://memimage.cardomain.net/member_images/1/web/685000-685999/685533_62_full.jpg

From the numbers stamped into the end of the heads, they are 290cc '502' replacement heads.

I have a S/A porting kit that I've been using to polishing the chambers and exhaust ports. I've also been using it to blend the seats into the bowls. I've also used a carbite cutter to remove several spots of flash on the exhaust port and several sharp spots that could cut someone.