I'm having a LT1 vortech 350 built. Vortech heads (Duh) with 1.94/.150 valves. Its going to have around 10:1 compression, LT4 hotcam with 1.6 roller rocker arms giving me .525/.525 lift. I'm running headers and a 3.5 inch exhaust and an upgradesd TBI and TBI edelbroch intake, 4L60 transmission and 3.73 Positraction rear end. I'm wanting to be able to drive the car down the highway to work and the occasional run down the 1/4 mile track. So would a 3000RPM stall be good for this setup or higher? Would like to hear everyone's opinions. Thanks.

 

Sounds like a fun combination.

I think you're on the right track. I'd say a 3000-3400 stall would be about right. I'm hesitant to recommend a 3600 because headers + 3.5 exhaust + 3.73's = loud car going down the street. A 3600 stall is going to slip a bit higher in the RPM band and be that much louder still.

Going down the highway, all torque converters will feel and sound like stock. They're locked up. No difference at all.

A 3200 stall would be about perfect. With your gears, it will be just as streetable as a 2800 stall would be with stock gears. Your car will definitely move with that.

 

What are those heads like? Must be a new product introduction? Didn't know Vortech made heads; all I know of in their product line, is centrifugal superchargers?

What connection does "LT1" have with a TBI motor?

If you can tell us what you're actually doing, it would help us to help you better.

But regardless, that's a higher stall speed than you "need" for a cam that small, in a 350. Something more around 2500 should be adequate. All you really need, is enough to cure the "soggy bottom end" thing that comes from cams that are only slightly bigger than stock.

 

Excuuuuse me! LOL I misspelled vortec. I'm putting a TBI EFI on the LT1. The shop is going to drill and tap the vortec heads to take my 12 bolt Edelbrock TBI performer intake manifold. You think that cam is going to be to mild?

 

I'd use more around the 2400 range. All flash speeds aren't equal. Big name converters are expensive but worth it if you want something more than a DD. They should take all your specs and recommend which speed. They should customize it to you application, not just pull a standard part off the shelf and ship it.

And converter can be lockup or non-lockup type. It's very annoying to have a non-lockup on a DD gets old having a mushy response and 3000 Rpm slip all the time at part throttles.

Plently of good threads on here about converters and how they work.

 

Oh OK, so you're just using the GM Vortec heads then, I take it?

Yeah it's just a "spelling" error; kinda like, "it's just a capitalization error", but if you left the capital letters off, a phrase like "helping your Uncle Jack off his horse" might take on a WHOLE OTHER meaning. Language is a wonderful thing: it's a tool we all use that allows us to substitute symbols called "words", built up out of these little pieces called "letters", for the real thing; and if we all agree on what symbols to use and what each one means, then we can communicate clearly and without misunderstanding, and without having to have the actual THING the "word" represents in front of us. It pays to be accurate with things like that, especially when the error leads to ambiguity.

Sounds like you're spending a whole bunch of extra money, just to shoot yourself in the foot.

Don't be surprised if, after wasting the money paying your shop to hack up your manifold, if the manifold doesn't even COMLPETELY COVER the ports on the heads, LET ALONE match to them. Which of course WASTES the entire advantage of those heads... assuming the engine will even RUN at all.

If you have to ask if that cam is too mild, you're not ready for a "less mild" one. Learn to tune that one first. Even one that mild will probably require some tuning, and the tuning headaches only get more intense as the level of cam goes up.

 

I don't really see why I wouldn't want to go with the best cam for that setup initially. Why learn on one cam to only down the road change to a different cam when I am already doing a complete rebuild? That's a good point on the intake though. I didn't really think about the intake ports not lining up correctly on the Gm Vortec heads. The only other option I would have running the TBI EFI on that motor would be to get a GM Vortec compatible carburetor intake and put an adapter plate on it. Or the GMPP TBI EFI GM Vortec intake manifold. Was kinda hoping to use the Edelbrock Performer TBI EFI intake that I already have so I wouldn't have to spend the $400 for the GMPP TBI EFI GM Vortec intake manifold or "X" amount of dollars for the other. The owner of the shop said that he has drilled and tapped other GM Vortec heads to accept 12 bolt intake manifolds and he would only charge me about $100 to do it.

 

That's really the way to go, right there.

Yeah the difference between Vortec heads and prior designs is, they moved the intake ports about 3/8" higher up on the flange; giving the air a MUCH straighter shot into the valve bowl. That's where all their nice intake flow comes from. The ports are SO high up in fact, that the majority of older intakes leave a slice of them exposed above the EXTERIOR of the manifold. So don't bother wasting that $100. Just because he's "done it before" doesn't mean that it ACTUALLY WORKED, let alone, that it met the threshold for being "A Good Idea".

Instead, sell the TBI intake maybe on this site's classifieds, and buy a Perf RPM and an adapter. There's a couple of adapters out there; there's one you DO NOT want, I think it's the Holley but I could be wrong, whichever it is, it moves the TB to the front a couple of inches (why, I can't begin to guess), and none of the cables and stuff will fit right.

 

Thanks for the info. Because he said he's done it before I thought it would work well. Guess I'll just spend a little more and buy a GM Vortec compatible intake for a couple of hundred bucks then.