706 heads on a stock LS1?
706 heads on a stock LS1? I just bought a used camaro a few weeks ago and I know the guy was full of **** when he said it had 04 GTO motor installed because the EGR was still there. It ran good and with the intentions I have I bought it anyways. Well today I'm tearing the motor apart to swap a cam in and I noticed the heads are 706 casting. Isn't that from the 5.3l trucks? The last stud holding the coil pack rail on was missing on both sides so someone has been here before, and there are a few loose bolts on the exhaust manifold as well. Any way to check vin on the block to see if it's original?
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Back in the early LS1 days, the 706 head was the best bang for the buck.
When 706's are ported correctly with new larger 2.00 or 2.02 intake valves, 1.6 exhaust valves and good valve job, good springs, they are almost as good as ported LS6/243/799 cylinder heads. The 5.3/4.8 706 head was the go to choice before 243/799 castings became more available.
Any chance to check with prior owner of the engine and find out the history of the heads? You might get lucky and have a good set of ported 706 heads.
A correctly built and ported 706 will give any ported 241 a run for the money. The 706 is easier to get higher compression out of unless the 241 has the chambers welded up and is then CNC'd.
I had a set of TEA Stage 2 706 heads on my 99 TA for the last ~15 years and 128,000 + miles.
When 706's are ported correctly with new larger 2.00 or 2.02 intake valves, 1.6 exhaust valves and good valve job, good springs, they are almost as good as ported LS6/243/799 cylinder heads. The 5.3/4.8 706 head was the go to choice before 243/799 castings became more available.
Any chance to check with prior owner of the engine and find out the history of the heads? You might get lucky and have a good set of ported 706 heads.
A correctly built and ported 706 will give any ported 241 a run for the money. The 706 is easier to get higher compression out of unless the 241 has the chambers welded up and is then CNC'd.
I had a set of TEA Stage 2 706 heads on my 99 TA for the last ~15 years and 128,000 + miles.
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Back in the early LS1 days, the 706 head was the best bang for the buck.
When 706's are ported correctly with new larger 2.00 or 2.02 intake valves, 1.6 exhaust valves and good valve job, good springs, they are almost as good as ported LS6/243/799 cylinder heads. The 5.3/4.8 706 head was the go to choice before 243/799 castings became more available.
Any chance to check with prior owner of the engine and find out the history of the heads? You might get lucky and have a good set of ported 706 heads.
A correctly built and ported 706 will give any ported 241 a run for the money. The 706 is easier to get higher compression out of unless the 241 has the chambers welded up and is then CNC'd.
I had a set of TEA Stage 2 706 heads on my 99 TA for the last ~15 years and 128,000 + miles.
When 706's are ported correctly with new larger 2.00 or 2.02 intake valves, 1.6 exhaust valves and good valve job, good springs, they are almost as good as ported LS6/243/799 cylinder heads. The 5.3/4.8 706 head was the go to choice before 243/799 castings became more available.
Any chance to check with prior owner of the engine and find out the history of the heads? You might get lucky and have a good set of ported 706 heads.
A correctly built and ported 706 will give any ported 241 a run for the money. The 706 is easier to get higher compression out of unless the 241 has the chambers welded up and is then CNC'd.
I had a set of TEA Stage 2 706 heads on my 99 TA for the last ~15 years and 128,000 + miles.
Teching In
Joined: Oct 2020
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Apparently it's only the Castech 706 heads that crack. The 61cc chamber bumps compression to 11.1:1. The heads also make quite a bit more torque below 5000 rpm than other heads, and Richard Holdener has shown they make the same HP. It's the best stock head to put on an LS1.
TECH Fanatic
Joined: May 2016
Posts: 1,292
Likes: 436
From: St. Louis
Apparently it's only the Castech 706 heads that crack. The 61cc chamber bumps compression to 11.1:1. The heads also make quite a bit more torque below 5000 rpm than other heads, and Richard Holdener has shown they make the same HP. It's the best stock head to put on an LS1.
