Argh. I keep switching between putting a (new) 383 into my 65 or a LS6 (as in Z06 LS6). Honestly, I thought the LS6 would be the best but now I am having second thoughts. I want a powerful yet streetable small block.

I thought the LS6 would fit the bill. But it’s a heftier price tag and requires lots of electronics and wiring. The oil pan also needs to be massaged to fit. Then the sump pickup needs to get moved too (see http://www.hotrod.com/projectbuild/113_0308_power/index1.html). I did an EFI swap into a non-EFI car and the electronics were not fun. I swore I would never do it again (before the LS6 came along).

So now I am thinking that my original idea of a stroked 350 is a better plan from a wiring and cost standpoint. Some engine builders rate their 383 @ 440HP. Is this true and accurate? The LS6 rating is 405HP and they say that Chevy rated them low to begin with.

Which is better if I am trying to get the most streetable HP from a 350 based small block?

If you are willing to make all the changes necessary for the Z06 motor why not go Big Block?

It would be cheaper and more cubes is what you need to make streetable power. A 383 that makes the same power as a LS6 will be less streetable (not bad though by any means) and will get less gas mileage (if that is of any concern). A 468" motor could be pretty mild and still go 11's in the quarter mile if planned and set up correctly.

Don't get me wrong . . . I love my 383 and I drive it everywhere (as in 2 or 3 hour trips across the state), but everyone has a different idea of streetable. To me, a rough 850 RPM idle in gear, 8" of vacuum, and 12 mpg on the freeway is still streetable and is half the fun of driving a hot rod.

I guess weight is a concern. Also, what automatic trans is realiable behind say a 454?

I was thinking that with a 350 based mill it would be an easier install. I believe with a BBC all the suspension needs to be upgraded, correct?

Yes there are lots of changes when converting to a BBC, springs, accessory brackets, etc -- just like putting in an LS6.

There are lots of tranny choices that will live behind a mild BBC -- the same choices you'd have with a hot SBC. TH350, TH400, 700R4, 4l60E, 4l80E, 200-4R, etc. You just have to make sure whatever tranny you look at is built to handle the power you will throw at it (especially the TH350, 200-4R and 700R4 IMO).

Also, there are lots of good streetable 350 or 383 combos out there -- if you need some ideas just let me know.

PS. Personally, I'd prefer the TH400 is you are looking for a rugged 3 speed automatic.

Actually, yes, I would appreciate some suggestions on not-so-expensive 350/383 combos. Preferably crate/builder engines.

I did the build engine from scratch thing once before. I should have just purchased a crate motor and been done with it.

well I have almost 5 bigones into my 383, but I love it...perf rpm heads, 11-1 comp. big comp cams bumpstick. engine dynoed at 458 hp at 6200 rpm and 440lb.ft at same rpm.. plenty stout for a daily driver . Took a bit of carb tuning, and playing with the timing, but it runs great and strong., plenty streetable too. almost wish I went with the 292 cam, but my TH350 wouldnt like it..:)Check out Wheeler Performance in FL. I bought my shortblock through them.. good prices on good stuff. while an "LS6" would be nice ( not right to use that moniker on a smallblock IMO) you would have to get a hold of all the wiring, plus the other mods like you listed..if I had my druthers I would build a decent mighty mouse off a good short block.

383 gets my vote. Can be easy on the wallet and an easy install. graemlins/thumbsup.gif

David

I understand that the truck pan with the sump at the back is the ticket for putting a Z06 engine is an older Chevelle or Camaro. The 6 litre engine from the Silverado SS or Denali trucks might be another, cheaper, alternative. It is rated at 345 hp so power shouldn't be a problem. The heads are the good ones also.

I think I've convinced myself back into the 383. It's just gonna be an easier and simpler install all-around.

Does Wheeler (or anyone else) sell a decent 383 'crate' motor that I can just drop in and that has similar numbers to yours? I like the HP and esp the TQ numbers.

I think you said it yourself, cost standpoint, wiring and almost everything having to be fabbed. I don't think headers or some sort of exhaust manifold that will fit are even an off the shelf piece yet for an LS6 swap. Come to think of it, I think the motor mounts have to be made too.
The ZO6 is a well thought out combo from its tranny ratios to its 3.42 gear. I ran mine to 12.1 at nearly 115mph on tires only in July heat so its a plenty powerful motor. I'd say go for it but being mechanically challenged thats not worth much! graemlins/beers.gif

Eric68, I'd like to get a few of your 350/383 combos if you don't mind. If you happen to have one with a 170CC Edelbrock RPM head that would be even better!

yup... wheeler does offer complete turnkey 383's for about the same as what I built mine for if I recall.. (been a while). They have 3 levels of shortblock you can buy too.. one with cast pistions, rods and crank. one with forged pistons, rods, nitrided crank,. and the top notch one with all forged goodies. I bought the middle of the road one, 4 bolt main. forged rods, pistons, decent crank. balanced, assembled,painted..supposedly good for up to 13-1 comp ratios.. for 1800 beans. Talk to Clay @ wheeler performance. they have a site as well..I am not a sales rep or anything, just like what I got for my $..good luck!!

Here's the details on my current combo --

'72 350 truck block bored to 4.060, line honed and decked. (don't bore any further than you have to, 4.030" is actually better)
SRP flat top forged pistons, Hastings 1/16" moly rings. Make 11.3:1 with 64cc heads. 68 cc heads would be better and would drop compression down to 10.8:1 with a 4.060" bore or 10.7 with a 4.030" bore.
Eagle SIR 5.7" connecting rods, Clevite bearings set at .002"-.0025" clearance
Eagle cast 3.75" stroke crank. Extenally balanced
Heads are Trick Flow 23* heads with minor port work. Just a basic cleanup around the valve guides and bowl. Opened up slightly at the pushrod opening and slightly raised the roof of the port. AFR 195's or another head that flows 260I/190E cfm at .550" lift will work.
Combustion chambers are polished, my quench height is a tight .034" (pistons are .008" in the hole, using a .026" head gasket)
CV products oil pan (kicked out sump with internal windage tray and scraper)
Moroso blueprinted standard volume oil pump.
Cam is a custom Comp street roller. It is the XR286R street roller ground on a 108* LSA and installed at 104* ICL. The advertised duration is 286/292, duration @ .050 is 248/254*, .576/.582" gross lift with 1.5:1 rockers.
Comp Super roller lifters with High Pressure Pin Oiling (not the Endurex lifters). I have not run these long term so I don't know how well they will hold up (so far so good after 1000+ miles). Crower Severe Duty or Isky Red Zone are a lot more expensive but are a safe choice.
Comp 977 springs set up at 1.850". Spring pressure is 155# on the seat 400# over the nose.
Comp solid bar stud girdle. Not necessarily needed but they help valvetrain stability some at high RPMs
Crane Energizer 1.5:1 roller rockers. Crane Gold would be a better choice but the Energizers are good to 500# spring pressure.
Edelbrock Victor Jr intake, 1" open spacer. Minor cleanup work in the plenum and match ported on the top and sides only.
Speed demon 750 carb. Stock jets. Ram Air box by Air Inlet Systems.
MSD ignition (stock HEI will work with a good advance curve and super coil) 34* total timing all in by 2600 RPM.
Hedman 1-3/4" headers, 2-1/2" Flowmaster American Thunder Exhaust with Dynomax Ultraflow mufflers.
Coan 10" competition converter. Foot brakes to 3200 flashes to 3800+
Rear gear is 3.73 with Eaton posi. A 4.11 and 8" converter would go faster but would be too much on the street for my tastes.
Home built TH350 transmission.
Hoosier QTP tires. 26.4" tall, 10" tread.
SSM lift bars in back, Caltracs or good slapper bars work well too.

If all you want is 170cc heads and a mild 383 look no further than the Vortecs. An RPM manifold and a cam with right about 230* @ .050 will make a real nice TQ monster in the 2000 - 5700 RPM range. With the right stall and gears it would easily go 12's in a Chevelle.