I've been thinking about all the work I want to do to the 862s I bought, and the price is starting to get up there. I've heard that one of our sponsors sells L92 heads for $700 which got me thinking of other options.

862 option: Mill them .030, CNC porting, 5 angle valve job, maybe stainless valves. ($900-1000)

243 option: Mill to raise compression ($600-700)

L92 option: Mill to raise compression, 90mm intake setup ($1200+)


I know the L92 setup would be the most costly because of the change in intake manifolds, but I know they flow incredibly well. These heads will be going on a 5.3 with a 228/228 .588 .588 112 cam, which really needs a good set of heads to really make power. Would the worked over 862s be worth it, or would spending the extra money on 243s be better than wasting money on the 862s and all the work needed to make them flow better.


And yet another question. I am revving my motor to 6600-6700 with this cam. If I put a good set of heads on there, should I swap to a different intake manifold? I know the truck manifold falls off pretty bad up top.

 

You should buy my 5.3 to replace you old/tired motor.


I would think the flow of the L92's up top would benefit that cam.

 

you cant use the l92's on a 5.3 only 4.0 bore and up but the 243's would be nice if you had them milled.

 

Ahh ya, I forgot about that part

Looks like I'll be looking for a good set of 243 heads. Would it be worth it to do much work to them besides milling them?

 

yeah but I would think they would be pretty good just milled for a 5.3 but the more flow the better lol. also I would be trying to find another intake like you said.

 

Couldn't you just find some of the 243 heads off the new 5.3Ls? I haven't kept up to date with them, but I know they have a variation of the 243 heads.

 

yes they are the same casting as 243's the casting number is 799 most of them have one 799 and one 243 that I have seen.

 

I have an 07 nnbs with 243's. Not sure of the difference, but I'd do the L-92's if you can swing the 6.0 block.

A 6.0, L-92's, and a stiff cam can get you in trouble quick. I hear you can get 475 RWHP smog legal here in Socal easy with that combo, but since you live near the big D. You can get way more since Texas smog standards are apparantly none existant.

 

they do exist... but there are ways

 

anyone know what the difference is on the ls6 (243) to the 243's on the new trucks