Texas Noob

[txarkitekt]

If honing the heads will fix the compression issue, I would be weary that the block was overheated. Make sure the heads are done right by a trusted machine shop. Doing all new rings would be good... If you can get your hands on a good used Z06 cam, springs, and pushrods, then do it. If you plan on going FI (turbo), you might wanna reconsider doing 5.3L heads--because doing so will raise you CR--which is not good for FI motors. Spraying it would be a great idea, because the LS blocks hold up well to it. If and when you do a turbo, you might then want to reinvest in some 243 heads to go with it...

[PurpleMinivan]

Welcome! The only good thing about being up there is your very close to SDPC and TSP. Hook'em!

[dimeraider]

Sorry, I must not have been clear at first. The guy that sold me the block said that it needed to be honed, not the heads. The 5.3 heads are just until I do end up starting the turbo project, then I'll definately get different heads for that reason. So are those 243's stock on anything or strictly aftermarket and what is the number on the 5.3 heads (2002 Sierra)?

If honing the heads will fix the compression issue, I would be weary that the block was overheated. Make sure the heads are done right by a trusted machine shop. Doing all new rings would be good... If you can get your hands on a good used Z06 cam, springs, and pushrods, then do it. If you plan on going FI (turbo), you might wanna reconsider doing 5.3L heads--because doing so will raise you CR--which is not good for FI motors. Spraying it would be a great idea, because the LS blocks hold up well to it. If and when you do a turbo, you might then want to reinvest in some 243 heads to go with it...

[dimeraider]

Are the 243s on the newer 5.3 trucks? I think I read that somewhere a little while back.

[txarkitekt]

No, the 5.3L heads are the 862 casting.

[dimeraider]

Is the 243 aftermarket? What year is the 862 in? I thought that they had changed in the newer trucks.

[txarkitekt]

243 is the LS6 heads. You can tell the difference on them from the D-shaped exhaust ports. The 317 heads (sand cast) and 035 (die cast) heads
came on the the 6.0L (LQ4 and LQ9). 862 are the heads that come on the 99 and up 5.3L and 4.8L. Some also carried a 706 casting number, but very few had them.
The LS1's were 806, 853, and 241.

[Melissa@NelsonPerformance]

Great to have you here!