LS1IMPULSE

iTrader: (42)

I'm just finishing up on my F14 camswap and while I had the car apart I found out the previous onwer stripped the rocker bolt stud and had to helicoil it and cut the bolt shorter for it to fit. I dont doubt that the bolt will hold but its been on my mind for a while an so Im considering buying a new set of OEM heads. either the 243's which I know will also gain a few HP over the 98 heads or a set of 5.3L heads. My question is what do I have to gain by getting the 5.3L heads? I've also been told they will fit fine without any flycutting...anyone disagree?

9540x

I'm assuming your running an LS1? In any event, you'll gain compression because the ports of the 5.3 are about 57cc ( I think, you should double check on the exact number, but they are smaller than LS heads). Compression should go to about 10:1, 10:5 depending on the rest of your setup. You shouldn't run into any compatibility issues though because the 5.3 is the same block as the LS1-6

DesertFox

iTrader: (2)

As far as I have found the ls1 and 5.3 heads are the exact same except for the smaller combustion chamber and smaller intake valve. If you want to use them get a valve job and put the 2.00in valves out of your ls1 heads in there. the rest is gravy.

Josh

Studytime

iTrader: (15)

They have smaller ports that don't flow as much as LS1 heads. They're also cut for smaller valves. Not a good swap in my mind. The decrease in flow will negate the gain in compression.

Ben T.

LS1IMPULSE

iTrader: (42)

yeah thats what I wasn't sure about, I knew they would bump compression and HP from that, but wasn't sure if somthing else would cancel that out...I was leaning towards the 243's, I can probably get a few extra HP goin from my 98's to OEM 243's

Studytime

iTrader: (15)

Yes, you could. That would be a really nice upgrade for your car.

Ben T.