Greetings, just discovered LS1Truck.com and digg it already! I have 03 Chev 5.3 LM7 in a shortbed reg cab and recently purchased a LS2 6.0 shortblock. After reading forums and talking with the local GM dealer I still have no clear answer to:
Will the top end of a LM7 5.3 bolt up to the shortblock of a LS2 6.0?
Without going into lengthy explaination of why; the blending of the two engines would be a temporary solution to a $$ money planning problem.
Thanks in advance ... -Toby
all cathedral port heads will bolt to the 6.0. 6.0, 5.3, and 4.8 intake manifolds are the same.
Last edited by cjriojas; 08-15-2010 at 02:03 AM.
'02 Silvy: Z71 EC Step Side 5.3L Nelson tuned
2013 GMC Acadia: SLT1 Carbon Black
1976 Corvette Stingray: Trying to save it, progress is slow.
^Ricky's Sweet PS Skilz
09/21/2010 02:31 <danger_ranger83> I'm not really worried about the looks...I want it to be fast and ugly...bc no one wants to get outrun by something ugly
The 862 heads from the 5.3 aren't gonna be the best thing for the LS2, but they will work. I would spend the few extra dollars to find some 243s at least.
Will the 243's work with the LS2 pistons? Won't those heads push the cr over the limit?
799 cast heads came on the Ls2 which are pretty much 243's.
'02 Silvy: Z71 EC Step Side 5.3L Nelson tuned
2013 GMC Acadia: SLT1 Carbon Black
1976 Corvette Stingray: Trying to save it, progress is slow.
^Ricky's Sweet PS Skilz
09/21/2010 02:31 <danger_ranger83> I'm not really worried about the looks...I want it to be fast and ugly...bc no one wants to get outrun by something ugly
799/243 heads on a LS2/LQ9 put you at 10.9:1 compression. No where near pump gas limits. Don't waste your time with those junky 5.3 heads on the bigger bore motor.
The 5.3 heads have even smaller chambers than the 243's. Not sure what it would bring you up to but I'm sure its past the limit of pump gas.
NO its NOT i ran 706 castings heavily ported heads, if i remember correctly the cr was just over 12:1Originally Posted by bowtietommy
it put down just over 400 on my lq9
Simple: 408 on steroids!
single digits coming soon!
12:1 sounds pretty high to me without a big cam to bring down the dynamic compression. But if it worked for you that's good to know. Also I might be wrong about this but I thought the LS2's had a domed piston and the LQ9's were a flat top
LS2 and LQ9 have flat tops, LQ4 has dished
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