Hey guys I have a pristine completely stock 72' 4 bolt main 511 cast#400 short block.It was a complete running two barrel engine when we pulled it.I would like to have the block cleaned,decked and bored if necessary.I want use hypereutectic pistons and 5.7 rods with the stock crank and have the rotating assembly balanced.I want to run a good mechanical roller cam,some good aluminum heads and intake.I want the static compression to be 10 to 10.5 so I can run 93 octane pump gas with no problems.Then top it off with 750 double pumper and some good full length headers.Would this set up last in my 1990 GTA as a street/strip bracket racing engine that wont be revved over 6000 rpm.The trans is a mildly built 350 turbo with a 3500 to 3800 stall converter.Come on all you hotrodders tell me what you know..All thoughts and comments are welcome and appreciated...

 

If you are planning to keep the rpm down and run the stock crank with cast pistons you probably can keep the build milder. That's a pretty high stall for a lower rpm motor. I would highly recommend at least going with a scat crank and rods, even if you run cast pistons. It's probably cost effective considering the regrind and balance. I kind of went the other way around. Aftermarket block, forged stroker crank and forged pistons for a street motor that sees nitrous and occasional strip use.

Having said all that, here's my top end. I ran AFR 210 head with 75cc chambers. With flat top pistons and thin cometic gaskets (for quench) I ended up at 10.4 static. My cam is a 236/242 hydraulic roller and I have no problem on 93 octane gas. Others may be able to comment on the induction as I run fuel injection but a Victor Jr would likely be a good choice with a mech roller in the 240/250 @.050.

 

Hey man thanks for the info I've owned this engine for a while and I'm just trying to figure out what I might do with it.

 

Ive been wanting a 377 for a while. Im not really a fan of "Destroking" so much as I am a fan of lower piston speeds. It should be slightly happier at mid to high RPM's that way. Been wanting a build like that for an autocross/road race situation for a while. Plus you dont have to worry about cam clearance and clearancing the block for proper length rods and so on, all hte stroker issues you will have. Just a simpler build that way, and you get the benefits of a larger bore. Should theoretically be faster than a similarly set up 383.

But it is my understanding the 400 bores are just prone to shifting around and distorting from run to run. Not going to make the most consistent max effort race motor that way.

 

Your plan is solid, except I don't think it's cost effective at all to go mechanical roller for the relatively low rpm use.
Definitely keep the stock crank.

 

Yeah I'm running hydraulic rollers and like them.

 

From what I've seen and heard a 377 sounds like it would be fun.I'm not going for max effort race motor just a pretty stout street/strip bracket race motor that runs good on pump gas.So are you still running your vortec head 355 ?That's what I'm running now.

 

If you're not turning more than 6000 rpms AND not running some outstanding cylinder heads, forego the 377 idea (sexy as it may sound ), and stick with the extra cubes - all around much better for a street/strip motor.

 

Yeah the solid roller probably is overkill and I don't see this engine becoming a 377.I see from your profile that you have an LT1.I have an Lt1 engine that I bought about a year ago.I haven't tore it down yet but from what I can see with the oil pan off and from what I was told it's a 383 with a pretty serious looking rotating assembly.Just another future project..

 

Do you mind telling what your bore,stroke,deck height and cam lift are?And did you have to use a small base circle cam?

 

My engine is a 4.125 (std) bore 3.875 stroke with 9.015 deck (~414ci) with .380 lobes. If memory serves me it's a .950 base circle which is smaller than stock. I would need to look at my cam card as it may even be .900. I did not assemble the engine so I don't know if the small BC was really necessary. We used callies rods which are supposed to clear modest lobes on a stroker 400. This is one of the areas where I wish we had checked first but time was getting tight and we went ahead and ordered a small bc cam to make sure. If I ever replace the cam I will put the largest BC cam that will still fit. Check it first.

 

Just in case, add the third starter hole if it doesn't have it.

 

Thanks for sharing man.I think I'm gonna go with the hydraulic roller like you did.This motor will likely have a 4.125 or 4.155 bore and a 3.75 stroke.I will also be looking at a little less stall.The 3500 to 3800 works real well with the 355 at the strip but it's a little loose for the street.

 

need to edit that bore size to 4.125

 

Duh I guess I built too many 350's lol.

Good catch- thank you- edit made.

 

If you pick your rods carefully you should not need a small bc cam with 3.75 stroke. Scat, callies & others make them that will clear. But check first to make sure. Even some grinding on a rod bolt head or two isn't the end of the world.

Even though my Dart block accepts the late model (86-99 lol) factory hydraulic roller lifters, I went with the comp cams retro fit short travel "race" lifter. They have less travel inside to address collapse/pump up issues. The roller is larger diameter and they look like HD pieces. I haven't found any detriment to using them. And honestly, I put around 300 miles per week on it weather permitting. It's not just a street licensed car but my main vehicle. I have a 2002 PT that basically sits in the driveway waiting for rainy days.

I think a 35-3800 stall would be terrible to drive on the street in a true DD. I went from stock to a mild (2400?) stall on a big block 72 Camaro I had and hated it. It felt so mushy and made part throttle shifts seem stock. But to each his/her own.

 

Agreed. The only TC in that range I find acceptable for DD is a Yank SS3600; it drives almost identically to a Vig 3000.
The other thing to keep in mind is that a 12" TC advertised as being over a 2300-2400 stall is likely to drive worse than any decent 9.5" TC in the 2800-3200 range.
Ant, If you're at a dragstrip/ car event around there, keep an eye out for this one:
It's the car in my sig, my daughter's; she lives in Huntsville now.

 

You are right the 35-3800 converter is terrible on the street.But I don't drive this car on the street much.I trailer it to the local drag strips and play around,the converter works real good there.I do know that when I go to the 400 I will need to go with a tighter converter and less gear ratio.I like to stay on pump gas to keep cost down.Thanks for the info on the scat rods and comp lifters.