I've attached a link for an LT4 crate engine. Would this be a direct bolt in for a 95 Z28 convertible. Will my LT1 intake and all accessories bolt on? My LT1 has 240,000 miles on it and is very tired. I figure I could buy this and and swap it out in just a few days.
What do you think.
Ron
http://paceperformance.com/index.asp...D&ProdID=43322

 

Yes

 

If those are LT4 heads on there, the LT1 intake manifold won't bolt right up to it.

 

Good point

 

The crank damper hub will most likely be different as well, but could be swapped from the old motor.

 

Actually, I think it will, won't it? It's when you try to put an LT4 intake on LT1 heads where it won't bolt on because of interference. The LT4 head should already have the relief in them to clear the LT4 manifold, so, it should clear the LT1 manifold, too. I'm not saying this from experience, but I think it will work. You would probably want to port match the intake to the heads, though.

 

Aren't all LT4s set up for vented opti also. Are 95 LT1s vented?

 

Good point, I had a fit of confusion and was thinking of the LT4 manifold going onto LT1 heads. This brings up a question though, if modification is required to get a LT4 manifold to fit LT1 heads, then is it possible that even if the LT1 manifold clears the LT4 heads, that there may be some gap in there? I don't know this from experience either and am now curious.

 

as far as i know the lt4 will boltup to lt1 heads and i'm assuming vice versa. a friend on mine "DubbyZ28Camaro on this board" put a lt4 intake on AI LT1 heads for his 383 and runs with out issue. i thought the only difference was the .01 higher runner and the fact the lt4s are 195cc ports vs. 170 on the lt1.

 

yes, f-bodys 95-97, y-bodys 95-96, and b-bodys 94-96 were vented

 

No, an LT4 manifold will not bolt up to stock heads. Aftermarket heads, maybe, if they are machined like the LT4 head on the intake maniflold side.

 

There should not be a gap, but the port may not line up exaclty. IOW, you might have smaller outlet on the intake manifold dumping into a bigger inlet on the head.
See this for a comparison of the two heads. Just under the "B" in the cutaway pic of the intake side of the LT4 head, you can see where the mating surface is taller than the stock head. The LT4 manifold is made to mate to that larger surface. If you look at the stock cutaway pic above that, you can see that an LT4 intake would hit on the portion of the head just under the valve cover rail and not be able to lay flat.

 

Thanks, If I decide to do this I'll probably buy the LT4 intake too.
Ron