I would like to swap a set of alum. 87 Vette heads onto my L03 in my Caddy. I have a couple of questions. Will these heads bolt right up? Will egr still function? What will the lower cc's bring my comp. ratio up to? Should I just use these on my 93 mtr. in my F-car? Please list any problems I may run into........Thanx

 

almost. no. same. if you want. The 4 center intake bolts are at different angles than your stock heads. The holes on the intake need to be elongated to match.

 

You'll have the plumb the EGR off an exhaust manifold and run an external egr to the intake manifold.

 

Why would you want to put inferior heads on an LT1? The vette heads are not made for a reverse flow coolant system anyway. Put them on your caddy along with an LT1 cam. Actually you should put the big block in the caddy .

Steve

 

The aluminum heads, if they are L98, are probably better than the iron one on your '91 Caddy... so yes, it is a good idea. And you DON'T want to put them into the Fcar: the LT1 is reverse flow cooled in the heads, and the aluminum ones are not (as stated above). L05s are not reverse-flow cooled.

That said, I do agree -- if you are going to change the heads (a good idea, less weight, looks cool), then you should change the cam too. Use a 94-96 Bcar LT1 cam. You should be able to find one easily enough. You should also add a good cold air system to the TBI. There's a thread on this forum that discusses it (do a search with the keyword cold air LO5 caddy ). The combination will work great. - Ken

 

Maybe I need to be cleared up....the engine in my Caddy is a Chevy 305 TBI, L03...correct?? NOT an LT1. I already have the Vette heads w/a fresh valve job. The 93 engine in my F-car was a 350 TBI eng. converted to carb. The center bolts on the intake on the Caddy eng. already are at a different angle, so the heads should bolt right up..right?? How do I convert to an external type EGR? Does anyone know factory part #'s or a aftermarket kit to do this?
I have done a few recent mods to the Caddy, K&N filter, test pipe-flowmaster, 2,400 B&M converter & Hi-perf. trans rebuild.
What should I do when I do the head swap & LTI cam? Intake, adj. fuel press reg.?
I love my Caddy...it's just too slow .......well I did run a 17.0 @ 79mph before the converter & trans rebuild, not too bad I guess for a 4,400 lb. car w/3.08's and a TBI 305

 

The Caddy engine is either an LO3 or an LO5. Check the SPID label in the trunk. LO5 = 350 with TBI; LO3 = 305 with TBI. I thought the 350 was std in the Caddy, but I'm really not sure. Your timeslip does suggest LO3.

Correct, it is NOT an LT1 (that would only be on the 94-96 Fleetwood D-platform or the 94-96 B-platform, or the 93-97 F-car platform or the 92-96 Ycar platform (Vette); you have a '91 D-platform Fleetwood) so you have either LO3 or LO5.

You asked if the heads could be used on your 93 Fcar LT1 engine - no, they can't.

I know you have the heads and they'll work fine on EITHER the LO3 or the LO5. External EGR will require an EGR-compatible intake manifold and either an exh manifold with an EGR feed, or use headers and weld a feed bung onto them. I think that PACE has a kit that does a Vortec head conversion on LO3/LO5s, so the exh manifold from that application might work for you. Check their web site.

I'm sure that the external EGR question has been asked before on THIS forum so you might do a search for it.

The K&N filter you have probably fits into the stock air cleaner box, and that's not a very good one (the air box). Read the other TBI cold air intake posts -- there are several choices that you could use. If you are sticking with the carb conversion, then you will need to adjust the FP because the carb probably doesn't want to see more than 5psi. I don't know if you will pass emissions with the carb, so it may not matter that the EGR isn't working..... and that could be a major problem for you so you better think about it now before you spend any more $$.

Also check out the Fleetwood forum section at

http://www.impalassforum.com/cgi-bin/ultimatebb.cgi

for chassis and suspension mods you can make, as well as the engine mod stuff in the Engine Performance, and in the Caprice forum on the same website. Most of the copcar suspension stuff will bolt onto your Caddy, and you can get the used parts cheap.

The heads, cam, and a little tuning ought to get you into the mid- to high-15s with the LO3. There are Fcars running LO3s that run in the 14s so you should be roughly a second slower given the extra weight. HTH. - Ken