My friend gave me an intake manifold off of a caprice, and from what I can see with mine on the car is they look the same, I just wanted to make sure the 97 LT1 intake manifolds are the same as the Caprice intake manifolds before I send it out to be ported.
Thanks in advance.

 

They are the same.

 

It's the same if it's from a 5.7L (LT1). If it is from the 4.0L or whatever the smaller V8 was, the L99, then the ports are slightly smaller but can be ported to be the same as the LT1.

 

262/4.3L

 

Holy crap! How much smaller are the ports? Where are they smaller? I have a 4.3L manifold on my car right now. That could be my horsepower restriction on the top end. I was planning on welding and porting this manifold very soon for my LE LT4 heads. I am very curious on this!!!

 

I actually measured a 96 L99 intake and it is NOT a problem, hell it is what is on my car now though I did have AI port it.
The ports are 2.04 tall and the width tapers from 1.07 to 1.17, does that seem exessively small to anyone? I have an LT1 intake I can go measure.

95 LT1 intake measured 2.04 by 1.13 no taper, I have heard some of the LT1 intake had a little bit of taper to the port width as well.

People want to make WAY WAY too much over the minor differences between b-bodies and f-bodies and the L99-LT1. The L99 is definetely a different motor but shares identical architecture and a whole lot of parts. For those of you who get a hardon over long rods the L99 got 5.94" powdered metal rods rather than those crappy short ones the LT1 got . My motor also wears an "L99" oilpan and fuel rail/regulator. My wagon has some homeported L99 exhauist manifolds on it, I was less after the ported manifolds and more after learning to use the diegrinder and burrs on something I wouldn't care about damaging. Hell the tranny in my car is the L99 one rebuilt. A friends stroker has the oilpump drive and another guy has the L99 rods and crank in an LT1 with stock LT1 pistons to make a 302ci Chevy the shorter stroke makes up for the longer rod and the stock LT1 piston ends up being correct , but yeah you guys keep worrying about how wildly different all that stuff is .

 

If you could measure a LT1 that would be cool. For curiosity's sake. I had planned to weld a little bit at the top of the ports to mate with the LT4's. I never really paid much attention to the port size, it was a while ago. Thanks.

 

Look back I just edited the post and put the info there.
I will say I have seen at least 5 different LT1/L99 intake casting numbers listed as approved on the IHRA site.

 

So even though the ports might be smaller cast, they both can be opened up to the same size when ported?

 

Yes, no problem whatsoever it is a tiny amount and I am sure that taper is there on some LT1 intakes anyway. Besides it isn't like a head where you could hit water or something.