As said above dose the L99 (4.3L) version of the LT1 use the same intake manifold? Has any one done the conversion with that manifold before?

How about the runner dimentions for the LT1? I only have access to L99's here and mostly I dont want to cripple my car with under sized runners. If somone has the height/width of the LT1 IM I'll compair the L99 before I buy.

Thanks.

 

google it ,lots of answers,jimmy

 

yes,it is the same

 

I also wasnt sure about the intake differences, and i thought i have heard you couldnt use the L99, but i guess that is false? I'd have to look it up

but make sure they dont use the fuel crossover in the rear, you need to have it in the front for the conversion to work right

 

The Caprice version of the intake never bolted to aluminum LT1 F-body heads. Caprices used cast iron heads. Heads that are basically cast iron Vortec heads but with a different intake bolt pattern and reverse cooling.

The intake ports on those Caprice engines are a lot more like LT4 F-body heads and Vortec truck heads, with respect to the intake ports (taller. skinnier than earlier intake ports). I'd measure carefully before bolting them onto anything else to make sure the ports line up.

Can't say for sure if the "little brother" Caprice L99 engine has the same ports as it's bigger brother LT1 Caprice motor, but it's worth actually checking before you make the leap.

 

Thanks for the replies. I'll search the LT1 forums when I have time to see if people have used L99 IM's or heads on LT1's.

 

https://www.thirdgen.org/forums/alte...305-heads.html

Anything John says about those intakes I would take pretty seriously.

 

Thanks for the link. That pretty much answered all the questions I might have had to follow up with. To bad the pic link wasnt up.