i am picking up a lq4 6 liter tommorow that will eventually end up in my 86 IROC but i am new to the lsxs so im not completly sure on what all interchanges between them.
there is someone locally selling a ls6 z06 clutch and im not sure if it will work since the vettes are transaxle.
also it has heads from a 5.3 on it im not sure of casting numbers and am wondering if im better off with those or ls1 heads.

if anyone can help me out please let me know

 

What year is the engine? The first 2 years had a different length of flywheel mount on the crank, so the LS type clutches won't work on them. If one of the later ones, the LS6 flywheel & clutch will work.

LS6 or LQ4/9 heads would be better than the 5.3 heads.

 

its a 2001

 

Unless those 5.3 heads have been CNC ported by one of the big-name, nationally-known porting shops.

 

I believe that has the long crank output flange then. An LS1 crank will swap in if you want to go that route.

I guess I missed the part where he said they were 5.3 heads CNC ported by one of the big-name, nationally-known porting shops...

 

Do you know what the difference between the two is just so I can be sure

 

And no they are just stock heads from a 5.3

 

I did specify: "unless".
IDK if they all stamp their logos into both ends of every head, or what, but it is a popular way to get flow with compression. Better than milled but un-ported 243s / 799s.

 

5.3 heads dont flow as amuch due to smaller valve sizes compared to the 317 castings often found on truck motors i believe. 799/243 heads are very similar but have smaller combustion chambers than the 317's for more compression. Those are often found on LS2 motors. If you can score a set of those, go for it. Even 317's make a nice head once milled down abit for more compression.

 

Look at the crank flange under the flexplate. If the flange is approx flush with the RMS, you can use whatever clutch you want. If the flange sticks out approx 1/2" the crank needs to be changed

 

Just finished unloading the motor. The back of the crank is almost flush with the back of the block would that mean id be able to use a ls1 clutch/flywheel

 

didnt read this before i posted.