Hey I have a friend that has a 95 formula and he's wondering if you can run an lt4 intake on lt1 heads. I don't see a reason why not but i'm just checking. Also is the lt4 intake manifold that much better than the stock lt1 or what? Thanks for any info!

Jake

 

The LT4 intake will only work with LT4 heads...the ports are different and won't line up.

 

Thanks! That's all I needed!

Jake

 

Wellll.....

The LT4 intake won't fit on the LT1 heads, but not for the reason given in the post above. The problem is that there is a mechanical interference between the LT4 intake and the rail on the head for the valve cover. Either the intake or the heads can be machined to remove that interference.

But that won't gain you anything. While the LT4 heads have 0.100" taller intake ports, the LT4 intake does not. If you hold an LT4 intake against an LT1 intake, there is virtually no difference in the ports at all. The LT4 intake is a poor match to the LT4 heads, and takes major porting to support high flowing ported LT4 heads. The difference is that the LT4 intake has the extra metal at the top of the port that allows you to open up the port to match the LT4 heads. I think GM ran out of $$$ when they were designing the LT4

 

I agree, even though lots of eveidence on the net suggests the 330hp rating was low about 15-20hp (most dyno between 300-310rwhp like LS1s) the LT4 was an easy 380hp engine from the factory if GM would have really utilized what they developed. All they needed was a better exhaust and larger cam... just like the LS1 used.

 

IIRC the LT4 Hotcam was originally intended to be the factory cam, but dropped for streetability. Either way, GM was already afraid the LT4 would cut into C5 sales so I think that is a major reason for the underrating.

 

Sorta sounding like me. I actually believe, some injuneer(s) started pulling their hair out, after finding out some 'bean counter' didn't want to spend the money necessary, to follow thru with what they wanted/had planned. Ah, the believing part, was for the bean counter action, not the hair pulling.