243s on lq4. what can i expect to gain

[cottontop11]

Engine has a 222/226 587/598 on 113+2 EPS cam. The heads are off of a TBSS. What should i expect with these heads and a np retune

[AFSP1211]

I think gains would be minimal. Maybe 10-15 due to the reduced chamber volume causing a bump in compression ratio. Other than that, they're pretty much the same head. Have you checked a compression ratio calculator to see what your final CR will be?

[kerrige]

If they were worked it would be significant maybe 30-40hp, however being stock they are good for maybe 20hp. I would get a P&P job done on them first if you can.

[Show&Go]

The 243 head is a good flowing head already. If 243 can pick up hp over a 241 on same motor I'd figure you would pick up more then 10-15 since I believe the Cr will bump up almost 2 isn't it? Read somewhere Cr would go to somewhere around 11 to 1. But I'm not busting out google search on it or nothing. Just trying to remember what I read before.

[canada4g63]

Have then ported matched and ported out and you should see nice gains. These heads can flow very good when done properly.

[Frenchy]

I have the same cam except on a 111LSA, with Patriot Stage 2 243s, on a 5.3, and it puts down the numbers in my sig, through a stock exhaust manifolds to muffler.

[cottontop11]

Im taking you guys advice. Heads going to patriot performance for full cnc porting and valve job. Might as well do it right. Plus patriot is only 100 miles from me.