I did a search but didn't find anything. Are the intake manifolds on the Caprices the same as the f-body intakes? I'm considering doing a LT1 conversion for my GTA and know someone who is planning on going carbed in their Caprice, so I thought I might be able to pick up the intake fairly cheap. But, I didn't know if it was the same as the f-body LT1 intakes.

 

You have a L99 intake from a 4.3L V-8 Caprice. It is known as the "baby LT1". Externally it is the same as the LT1 intake. The only difference are the smaller intake ports. This can be fixed by some port work.

 

Are the fuel rails (I. D.) the same from the caprice to the F-body?

 

The LT1 intake we put on my brothers car came from a 4.3L Caprice. However, it was the 5.7L casting. But either way, yeah, it'll work once converted.

 

The fuel rails are exactly the same for a L99 and LT1 no matter what car they come from with the exception of the Corvette LT1.

Remember LT1's were found in many GM vehicles.

 

Casting numbers are the only real way to be sure for the untrained eye. I can spot a L99 intake a mile away though.

LT1 casting number 10108630

L99 casting number 12552138

LT4 casting number 12550631

 

Thanks for the info, John. What about the internal plenum volume, is that different?

 

Nope, the internal volume appears to be exactly the same.