rmkvsgsxr

I just recieved by first corvette stingray 1972 T-Top. The previous owner stated that it was 350 bored over 60, Hust shift kit and headers but did not have any paper work to show the work was done to the enigne. I will like to upgrade the carb, air intake and the rest of the enigne to get some more power out of it. Just want to know what would be the best performance upgrade for the money. Any help would be greatly appreciated.

Rally68

First let me say that I have not done one of these engines...if I have the money this winter I am going to stroke & bore my 327 to a 383 with new heads, cam, & intake. Roller lifters, roller rockers and headers.

Based on the reading I've done, and assuming you have a good carb (qjet) now, I'm guessing that your best bang for the buck will be heads. I'm sure there are several members that can recommend heads depending on your price range.

Another thing to consider is the rear gear. I went from a 3.08 to a 3.73 and really like it. That change equals a 21% increase in rear wheel torque--I could definitely feel the difference.

Easy Mike

Best upgrade for the money? Tune it.

What's wrong with how it's performing now?

Tim H

I jist doun't kow wat 2 saz again!!!!!

billla

More information needed - do you have a casting number from the heads? What intake and carb is already on it?

I agree with Mike that I'd start with a solid tune - more HP lost with a bad tune than anything else

Rally68

It's all well and good to poke fun, but if you've identified a problem with what I said, I'd appreciate it if you'd share your knowledge

69 Chevy

If I remember correctly 327's had small journal rods. Some folks don't think they're up to the grunt a 383 can produce.

Rally68

I have a late '68 that SHOULD (again, I haven't been in there) have the large journal crank. I have been told I should bag the matching motor and stroke a 350 block, but the 327 needs a refresh and I know I won't have the money to do 2 motors plus I don't have anywhere to store an engine

sorry if this is a hijack

Tim H

You can't make a 327 into a 383.

billla

I haven't done it or even looked at the concept, but the bore is 4.00, right? I don't know if there are small-journal cranks, but if it has large journals, why wouldn't a standard 383 crank fit?

Rally68

Yeah, you can. The large journal 4-inch blocks are all very similar--in fact I've read more than once that GM made engines of 302, 327 and 350 inches from the same casting number.

Most people who have done it seem to agree that the 327 block needs more clearancing (grinding) than the later 350 blocks, but you absolutely can make a 383 from a 327. There are even kits available to stroke a small journal 327.

69vettester

I think the problem would be , the integrity of a 327 block would be seriously compromised at 383 spec's.

billla

If structural integrity is the concern due to additional clearancing, a bit of HardBlok at the bottom of the bores would address it and be relatively inexpensive.

If it was me, I'd still start with a newer, roller-cam capable block as they're pretty darn cheap...but it seems that it could be made to work.

scottyp99

You should be able to pick up a post '87 350 block somewhere, eventually, for pretty cheap money, use it as the basis for a 383. Single piece rear main seal, roller cam 383 with some nice aluminum heads on it would be a pretty sweet powerplant!


Scott

Rally68

vettester can you elaborate? everything i've ever read has said the only differences between the 1968 large (rod) journal 327 and the 350 blocks that followed were 1: main cap size/shape (there were no 4-bolt 327s), 2: cast in-boss for a breather in the top rear of the block by the dist, and 3: crank throw. Cylinder wall thickness, main journal size, etc were the same because the castings were the same. If I am missing something please let me know. I'm going to be bummed if I can't do this...

Rally68

That was actually plan A but the motor thats in the car is original (& TIRED) and I don't have anywhere to store it, and I can't afford to do 2 motors.

billla

Is your 'Vette numbers-matching?

Tim H

By all means stroke your 327 to a 383.

scottyp99

Well, the biggest bang for the buck on these old non-computer controlled engines is to re-curve the distributor. If it hasn't already been done, you will be amazed at how much more power can be made by these engines just by adjusting the ignition advance.

You mention that it has headers, but does it have a dual exhaust system with at least 2 1/2" diameter exhaust pipes, and free flowing mufflers? That will give you a good amount of extra power for the money.

Scott

Rally68

Yes...

Forgive my thick-headedness in my earlier post...I said rods where I meant mains and vice versa...shouldn't try to post while at work; I can't do 1 thing at once let alone 2...

Also pls forgive the hijack...going to start a new thread