I aquired a 1988 core motor for free from a boat,my buddy works at a race engine shop,looked it over,pistons with small dish and 4 valve reliefs were in perfect shape,very little ware in the bores,he honed the bores,resized the rods,polished the crank,reassembled with new rings and bearings,new oilpump,short block is done,the heads that came on the motor are 6217,these are listed as 300 horse crate motor heads,hard exhaust seats,1.94/1.5 valves,64 cc chambers,chambers look like l-98 aluminum head chambers,I pocket ported the heads and bought a head renew kit from competition products,stainless valves,z-28 springs,new retainers locks,ect. These heads should give me compression ratio of 8.5-9.5 I aquired a used 1988 tpi hydraulic roller cam and related hardware .415/.430 lift and I bought 1.6 roller tip rockers,which should give me .460 lift,I think this head/cam combo should support 300 hp. I have comeplete 1986 tpi unit,wiring harness ,ecm from a 305 trans am,I have spent over 200 hours reading this website and bought 6 books on tpi,I have concluded the best bang for my buck is LT-1 conversion manifold or I was considering siamesing the stock TPI base,and plenum,I read all the material on siamesing stock base,lots of conflicting info,what is the final verdict on siamesing the stock base,would I gain anything on this motor by doing this? I am not going to buy any aftermarket runners,I just want to know which way to go,LT-1 manifold conversion or stock TPI with siamese base,pro's and con's please. This motor is going into a street car,goal is good mileage,some dragracing at the local strip,looking for 14.0's ET or better

 

I vote for you getting a used LT1 manifold (there is one for sale on this site complete for 150 bucks) and modifying it yourself. That is the budget way. Have your friend at the machine shop put the distributor hole in it, the rest you can do. Also, get a used LT1 cam and ditch your TPI piece.

Good luck!

 

are all the lt1 intakes the same,can I use one off any motor,4.3 and 5.7 maniflds the same as f-body manifold?

 

yes the baby Lt1 AKA the L99 intake manifold will work it is the same as the Lt1..
as far as the ex.manifolds if you can DEFINATELY get hedders,the Lt1 manifolds suck!

 

not trying to post to much misinformation or anything but, i have a buddy with a 95 lt1 camaro and i think the factory manifolds look like gold compares to a factory log style found on a 3rd gen car, just my opinion tho.

also no idea on the differences in the engine bays of 4th to 3rd gen cars for clearence running them and such but, by the looks i cant see them being worse 4 sure, definetly an improvement.