can i put lt4 heads on my stock lt1?? do i need to have something done to my intake?? can i use the same self aligning 1.6 rockers?? what springs do i need?? thanks for the help.

david

 

what i am most interested in is the intake manifold. can i do some porting to the stock LT1 and have it match nicely to the LT4 head. thanks.

david

 

The LT1 intake manifold's runners won't line up properly with the LT4 cylinder heads intake runners. I'm not sure if you could get the LT1 intake to work without paying way too much money (anything is possible with enough money). I highly recommend you get the LT4 intake manifold. If you don't like the appearance, you can have the paint removed.

 

You need the LT4 intake

 

thanks for the info guys.

david

 

Don't bother with the effort unless swapping the cam too, and when doing a cam you let that dictate the springs. On the LT1 the cam is the restriction, not the stock heads.

 

What you do as far as matching an intake to the LT4 heads, depends on your goals.

First off, the LT1 intake fits fine between the heads, with the ports lining up as well as the LT1 intake would. Fact is, regarding your '95 LT1 engine, (IF this is the engine you plan on putting theLT4 heads) you MAY very well have the earlier casting for the LT1 intake manifold/plenum. This means the original port shape and size (at the port flange) of your LT1 intake is such that they are LARGER than the port openings of the LT4 intake. The later LT1 intake castings, along with the LT4 casting, has a port shape, at the flange that is much closer to the shape and size of the LT1 head casting. The [as cast], port of the later LT1 casting, and the LT4 intake, are virtually identical. This means the later castings (and LT4 intake) will not have the mismatch with the LT1 heads, that the earlier LT1 intake/head combo had.

If you do not plan on doing porting, or port matching at the flange, of your intake, that is no advantage whatsoever, to swapping out the LT1 intake for the LT4. If you were to port match the Intake (roof area) to that of the LT4 heads, the extra as cast material, above the port roof, on the LT4 intake, would be needed to rasie the roof enuf to match heads. Unmodified, do not expect there to be enuf material on the LT1 intake, to rasie the roof, to match the height to that of the LT4 head. You'd be damn close to breaking thru. If you were to raise the roof of the port, on the head any amount, forget it, it would be breakout extravaganza. Rockers and springs are physically same size of both heads.

It is little short of amusing to continue to see the 'myth' of the LT4 head/intake combo, live on. I believe the misinformation problem started with poorly set up, accuracy wise, internet info sites relative to these components. I've been 'fighting' this 'disease' of misinformation, regarding the LT1/4 component issue, for a couple of years now.

 

Pontiac Enthusiast mag, Nov./Dec. issue 2002 did a dyno test on the LT 4 compents. The work was done at the More Performance shop on their dyno. Of course they reflashed the computer for optium performance..

Stock: LT 1 w/ headers & 52 mm TB = 293 hp / 331 torque

Add: LT 4 heads & intake only, using stock rocker arms= 361 hp / 378 torque

Add: Lt 4 Hot cam, roller 1.6 rockers, timing chain set= 429 hp / 419 torque

So there it is, any questions call More Performance @ 704-393-8241