Planning on buying an iron ls engine for my 91 Z28. ANy body done this conversion? Is it pretty much the same as LS1 conversion? Whats the difference between LQ4 and LQ9?

 

I want the LQ9 myself, but either is good. You will need the intake, accessories, and oil pan for an f body.... other then that the swap is all straight forward. A lot of people find it cheaper to use a 4th gen parts car.

 

LQ4 has dished pistons for 9.4:1, LQ9 has flat-tops for 10.2:1. Stay away from pre-'01 engines. Some later LQ4s got the better heads used on the LQ9s. Neither cam is desirable.

 

 

This was in the Tech General Engine forum. I moved it to the LTx and LSX Engine Swap sub-forum.

Try searching in this forum. Reading the LS1 swap sticky in the top section of this forum would be a good start.

 

I have been looking into a truck LSX swap for a while since they are relatively common localy and are cheap. F and Y bodies tend to be parted out privately and the drivetrains go for quite a bit of cash.

I'm willing to stick with the 60E trans and I can work around the accesory issues but I am wondering if anyone has actualy tried to fit the truck manifold in a 3rd gen?

At the rear it dosnt look any taller than the TPI manifold and firewall clearance shouldnt be an issue but clearance at the front might be the issue everyone is wanting to avoid, especialy in the firebird.

Besides the budget issue I have seen one or two dyno sheets that show the truck mani pulling 20+ CHP over a stock F/Y body manifold along with significant low and mid range torque.


I ultimately want to keep it stock looking but I could pickup a spare hood to hack up until I can get a low pro manifold.

 

Yeah, the truck manifolds are definitely good performers, but clearance is a factor. This link points to a thread that I started that shows how the alternator lines up with the truck acc'y. drive on a Firebird. It's been said that an RA-II hood will clear, but that's not exactly a budget solution...