My dad was asking me this question while pondering possible setups for his 02 Z and quite frankly I have no idea.

I know that the LS6 castings flow better, but that's about it!

TIA

 

I can't tell you where the exact differences are but I can tell you that instead of spending money on the ls6 heads take that and have you ls1 heads ported out, you'll have a had that flows more than the ls6, for the same price.

 

money is not a big issue here....

also, either way, the heads will be ported

I'm just trying to figure out what differentiates the two...

 

LS1
12559853 (99-00)
12564241 (01-03)
Combustion Chamber Volume:...........66.67 cc
Compression Ratio:............................10.1:1
Intake Port Volume:............................200 cc
Exhaust Port Volume:..........................70 cc


LS6
12564243 (01-03)
Combustion Chamber Volume:............64.45 cc
Compression Ratio..............................10.5:1
Intake Port Volume:............................210 cc
Exhaust Port Volume:.........................75 cc

All castings have 2.00" Intake and 1.55" Exhaust Valves.

 

thanks! thats exactly what i needed to know

 

If they're going to be ported either way then just go with the ls6 castings, I believe you can get another 20cfm or so out of them over a ls1 head.

 

The other differences are that the LS6 heads have D-shaped exhaust ports, LS1's are oval/round. Supposedly the D's flow better, the LS6 stock heads have lighter valves and retainers. But the cost of the heads, port job everything is more expensive. If money is no object, get the LS6's. If you are going all motor, no pwer adders later these heads rock!

 

I'm thinking of going TT (not so near future). I was also planning to get PACEs LS1 to LS6 conversion kit (heads and cam) by summer. Given that the LS6 CR is already 10.5 should I just keep my LS1 heads and just port them to flow better? Thanks.

 

dano if you plan on the tt route i would wait till your ready for the tt and get some nice 6.0 heads it will lower the compression and flow great.