Chevy Cowboy

iTrader: (5)

Originally I planned on doing a 408 for this summer, but the more research I did the more I realized it was out of my price range for this year. So I decided to just build my 6.0. So I qucikly realized I got many options. My 6.0 is a lq4 out of a pre 04 gmc, only 25,000 miles on it. Like most people Im not shooting for peak numbers but for a nice power curve. I would like to go all motor for as long as I can and if I have to add a turbo or procharger to reach my goals. Heres a few options Ive been researching.

Option #1 - Stock lq4 with a turbo cam, and just boost the **** out of it, not to sure how much horsepower I could net with this as theres many things to factor in

Option #2- Swapping out the lq4 pistons for ls2/lq9 flat tops to bump the compression up then add some 243 heads or have my 317s milled a small amount to get compression up between 10:5:1 or 10.9:1 and a cam/springs and rods

Option #3- Milling my stock 317s .030 get compression around 10.4:1, add a cam and springs/rods, Im assuming this would be the cheapeast route

Option #4- Take my 5.3 862 heads get 2inch valves worked in, and that should bump compression near 11.1 and once again add cam, springs, and rods.

I havent done to much extensive research yet so I dont have a very good idea on some of the other things like how big of a cam I can go with, but Im willing to run the appropriate size stall for that cam. Anyone have any other suggestions for my best bang for the buck or even a straigh up better setup? Suggestions would be greatly appreciated, Im looking at getting this build going asap, thanks

TurboBerserker

iTrader: (1)

You won't see any difference between 10.1:1 and 10.5:1, so leave the 317s alone. Besides the chamber size and sodium/hollow valves in some 243s there's no difference between 317s and 243s. It will cost you more for the head work than a set of used 243s I think.

How much do you want to spend and to what end? Is this a stop gap until you have enough to do the 408?

zero2sixT

iTrader: (4)

Right on man. Ive had this arguement with a few people. You can get a perfectly fine set of 243s for $400 or less. Most head work costs $500+. At least from what Ive heard/seen.

Chevy,

I'd say go with #3, but like Turbo said, leave the heads alone. Cam it, full exhaust, stall, then drive it. In the meantime, start accumulating 408 parts. I'd even pick up a new block to have the machine work done. That way you can have some fun, build the engine you really want, then sell the other complete to recoup some costs.

That is pretty much my plan. Im about to swap an Lq9 into my 03 rcsb. Going to do a cam swap, and swap to a tbss intake. Was going to go with 243s also. Then figured I was wasting my money with the heads, since I wanted to build a 408 with trickflows. Kinda wish I hadnt started screwing with the tbss intake also.

Chevy Cowboy

iTrader: (5)

Ok so you guys think I should just do a cam and springs/rods on the lq4 and drop it and start getting parts for the 408? Ok if thats the case I got a few questions about the 408, I beleive Id have to get my 6.0 block bored .030 over correct? Generally whats a good ball park range that a machine shop would cost to machine that much out? Also where should I buy my stroker rotating assembly and what decent (not the cheapest, but not most expensive) rotating assembly should I look at getting? I know I wont be able to afford heads anytime soon after buying the rotating assembly so how good will my 317s be on a 408? And the last question for now. Going with a 408 Ill definently be going ALL motor for quite some time so around what size cam would you guys recommend? I had a pretty good idea what I wanted for the 6.0 but have no idea what I should look at for the 408, so any suggestions, concerns or comments would be greatly appreciated.