799/243's on a 5.3??
 

searched around a bit and didnt find really what i needed. is it worth it to put some 243/799 heads on a stock bottom end 5.3? was just wondering if it would make more power or the chambers are different. going to to put a cam in and thought if the heads are worth the money to put on or it would be pointless do to compression.

The 5.3's are already low on compression, so I would not swap to the 243's without milling them. If you have enough PTV clearance with your cam choice I recommend milling the heads to 59cc's and using an 0.040" thick gasket. This would get the compression to 10.2:1.

Well 243/799's have been OEM since 05 IIRC so..... May be 06 but you get my point. You wanna head that flows 22xcfm or 26xcfm????

How do I find out if the cam is going to have enough PTV clearance.

The newer 5.3's also have flat top pistons versus the older design with a 7cc dish. This keeps the same compression with the 64cc heads. Do you want 9.5 or 9.2 compression ratio?

So if the heads are milled .030 it changes to 59CC?

The best way is to install the cam and measure the clearance. What are the cam specs(duration, LSA, LCA)?

228/230 588/592 112 lsa

thanks for the replies fellas, didn't want to mill the heads at all just wanted to kinda bolt them on but doesn't seen worth it to me for the money right know.

Milling only costs $50 dollars a head

yeah i know its not that pricey to have the heads milled. mainly just wanted the info about this set up.

Cool...is there any way to find out if my cam will clear the PTV on my setup?

yes, measure it. its the only way to know forsure.

well damn..so I have to spend the money and then find out if the cam will fit.

ill just take an educated guess assuming no responsibility.

with stock 243's the cam listed *should* fit fine.

Just buy the L33 from Randizzle, and call it a day. :D lol

i almost did, but id like that iron block a little better lol

mill them down 0.30 to bump um compression..