Having been back & forth with quite a few iterations, I have come to the conclusion that I took my car in the wrong direction for what I really want. {insert - getting old}. What we've figured out is - I have been spoiled by modern conveniences.

Currently running a 10" 3000 stall conv & 3.73 gears behind the 454 .030 motor, now want to build a grunt motor that will pull a 2000 converter and 3.08 gears with the AC on. Thinking along the lines of my .070 block for a 4.320" x 4.25" 498" motor. Reusing the ZZ502 heads and intake. Possibly even keeping the 1.75" headers. The kicker is the CR. Seems I have limited choices with these heads. I can go flat top for 9.25/1 CR, 18cc SRP dome for 10.92/1 which is way too much for what I want or KB now has a 12 CC forging available that will put it at 10.38/1, but that still may be too much for what I want. Ideally, I would like to finish up at 9.5-9.7/1 cr, guessing a .030-.040 cut on the heads may do the trick with the flat tops. Planning on resusing the hyd rollers and possibly even the 233/236 112LSA cam. I'm making an assumption that the added stroke and extra 38CI will bring my power band down a good 500-700 rpm. Am leaning to just using the flat tops and the lower CR. Making an assumption that the lower CR along with the alum heads and large cooling system should allow this motor to run real cool with the AC on.

Been discussed here before, but I haven't seen anyone really come forth with a grunt motor combo, ???

Have you thought about going with an overdrive tranny?? Even that 400 and 308 gearing will not be as highway friendly as those 373 gears and a 700R.
I ran 308 gearing and overdrive and could cruise along at 60 at 1550 rpm.
Dump the existing high stall coverter and gears and give your present motor a try.
I too hate the high reving motors. Give me a torque monster and street/highway friendly gears.
Your existing cam is pretty mild. My old cam was 236/244 @ .050 and it would pull down to 1200 rpm locked in 4th overdrive.
Dump the gears right now and give it a try. Also put in a stock torque converter.

OD trans is the way to go IMO.

The 4l80e w/the .75OD will make the 3.73's equiv to a 2.79 rear vs. a 3.08, and you can keep your hard-hitting 454. And, you dont have to go through the expense/hassle of changing out the rear gear. Everything can be done at home.

That cam is mild enough, and with a 200-4R and a lock up converter it would be like a daily driver.

Vince ran the idea of a the OD tranny by me, it is a possibility. And yes just a converter and gear change may do the trick just as it sits. So could driving a little slower! With the T400/10 conv setup it seems as though I am always at 3000+. Great for WOT. Ran it up the highway this past Saturday about 15 miles. Was running at 3500-4000 keeping up with traffic. There's no reason to run this motor that hard.

67RS502, you run the same tranny/conv/gear setup. Do you run much highway or is it just all around town?

Call Chris over at CK Performance and get yourself a 2004R and restalled D5 convertor (factory Turbo Buick convertor)
www.ckperformance.com

I certainly see the appeal to "K.I.S.S" with a TH400 and some 3.08's. It's been done before with great sucess. The car that I'm patterning my current build up off of is a great example of this. Please understand that it's not an apples to apples comparison, but you get the idea.

My friend has a '65 GTO that has full interior, steel wheels, etc....it looks like a resto ride. He uses 470 cubic inch pontiac with edlebrock performer RPM heads (used to have ram airs) and 10.5:1 compression. His cam is a comp hydraulic roller with about 240 degrees @ .050". The rest of the combo is standard stuff, Hooker Comps, 3" exhaust, X-pipe. He runs a TH400 with an 11" converter and 3.23 gears. He drives 70 plus miles to the track, bolts on his slicks and runs 11.70's @ 114 mph. He's been doing this for close to 20 years that I know of. His car is driven weekly and weighs 3700 lbs.

Like you, i've kind of tailored my build up to take advantage of the 496" and better heads (Brodix Race Rites). I'll be running a 2500 RPM stall and somewhere between 3.08's and 3.42's. Haven't decided on cam yet.

Good Luck,
Bill

I aggree with leaving the motor as is for now because the cam is not that aggressive and i would either go with an o/d trans or swap out the rear gear & install stock type or very close to stock stall converter.

Either way you have to change the converter if you keep the current t400 or get a new o/d trans so that cost is a wash.

With that in mind the real question is do you buy new 308 gear for approx $150 and pay approx $200-$250 to install them for an approx $350 -$400 total or go for the new O/D trans that will cost approx $1,000-$1,300 with out a converter that needs to be bought either way you go.

I would really consider going from the 373s and loose converter to 308 and tighter stock types converter which would be a considerable drop in cruise rpm and save you $600-$900 + going this route.

When i had the stock 308's in my car with an m20 muncie & 26" tires the motor turned approx 2400-2450 rpm & 60mph and approx 2750-2800 @ 70mph which is a lot better then the 3500-4k rpm you said your currently turning out on the open road with the loose converter and 373 gear you have.

I am currently running 331's with the m20 & 26" tires and it turns approx 2600-2650 & 60mph & 2950-3k rpm @ 70mph which is most gear i would evern consider running on the street without some sort of O/D trans. I am considering going back to the 308's because i am getting older too and find myself doing more longer over the road cruising these days and mis the 308's for that situation,my mild 396 motor was real happy at 65-70mph all day long with the 308's.

If dropping from 3,500-4,000 rpms at highway cruise like your currently running to approx 2,750-2,800 rpms is enough of an rpm drop for you when crsuing at 70mph along with saving $600-$900 i would go for the 308 gear and stock converter swap just as long as your current trans is in good cond.

But,if its worth the additional $600-$900 cost for you to drop the cruise rpm a more from 2,800 @ 70mph to like maybe 2,100-2,300 rpms at 70mph then go for the O/D trans because your motor could easily handle it. But i would think that going from 3,500-4krpms @ cruise to 2,750-2,800 rpms @ 70mph cruise with 308's would be a very nice drop in cruise rpm making the driving much more comfortable which would be enough to make you happy.

Scott

I like the idea of an Overdrive Transmission (200 4R, 700 R4 or 4L60E). What about adding a Gear Vendors Overdrive while retaining the Current Transmission and Rear?

I run the 200-4R behind the 383 in my Luv, with a 26" tall tire it turns
2000rpm @ 60 mph. I drive it all ova da place! Plus with the converter locked up
you dont feel the stall (locked up its like a stick shift car), and this is with a
10" 3000 stall.

Will a 2004r withstand 550-600ftlbs? Why not just go right to the 4l80e?

Qoute" The kicker is the CR. Seems I have limited choices with these heads. I can go flat top for 9.25/1 CR, 18cc SRP dome for 10.92/1 which is way too much for what I want or KB now has a 12 CC forging available that will put it at 10.38/1, but that still may be too much for what I want. Ideally, I would like to finish up at 9.5-9.7/1 cr, guessing a .030-.040 cut on the heads may do the trick with the flat tops Qoute"





That is exactly why I had my GMPP signatures machined to open chambers. I could have bought any head I wanted for the price of machine work I have in them after the combustion chamber and port work.

Joe, one input only if you redo the engine, go flatop, get the cr to close to 9.5:1 and run cheap 87 octane fuel. its a long hauler right? Tranny ideas make sense though. Why most new rides have 5-6 speed gears. At least 4!

200R4.

OD trans with a lockup conv. any stall you want, when it's locked you aren't creating heat & the mpg will improve too. 200-4r or 4L80E contact Jake or Chris.

IMO, retaining the 400, going with a 308, and tightening up the converter will still not get you where you want to be. Assuming 27" tires at 70 MPH it will be turning 2683 before factoring in converter slip. With 26" tires it's running at 2786.

With a 1:1 4th, 3.31's and 27" tires mine spins at 2883 @ 70 - much too high for me for anything more than an hour or so. Adding an OD of .75 would drop my 70 MPH RPM to 2163.

3.73's, 27" tires, and an OD of .75 results in 2473. An OD of .70 nets 2274. Very reasonable. Changing to 26" tires nets 2531 and 2362 respectively.

An OD trans is the only way to fly. Keep the 3.73's, use a 200 to avoid the horrendous 1st to 2nd differential that the 700 has. For zippy reference, below is the lsiting of auto's and their ratios:

TH-350 2.52, 1.52, 1.00

TH-400 2.48, 1.48, 1.00

700-R4 3.06, 1.63, 1.00, 0.70

200-R4 2.74, 1.57, 1.00, 0.67

4L60 3.06, 1.63, 1.00, 0.70

4L80 2.48, 1.48, 1.00, 0.75

Dan

Gene, yes it's going to be a cruiser, not a racecar afterall, not that it ever was. But, I want eyeball popping, tire frying at the blip of a throttle torque power. If I thought it wasn't going to be a huge hassle, I would go ahead and build the 4.310 tall deck I have with a 4.5" crank. Ironic, this is an easy combo to build. 6.535 rods, 1.395 pistons and a 4.5" crank are all off the shelf parts today. Hassle part is putting it in the chassis.

Will a 2004r withstand 550-600ftlbs? Why not just go right to the 4l80e?

a 2004R will handle that all day long when built correctly. There are 9 second Buick Gran Nationals running these transmissions.