stock 4.8l - cam 5.3l

[molitor]

I don't see why you are going to need a new ECM just because you are going from 4.8 to 5.3, it would run fine with the 4.8 tunning, for now anyway. Get with Nelson Performance and talk with Allen or shoot him a PM on here. He can set you up a tuned ECM for your truck and mail it to you, then you either send him back your stock ECM or pay the core charge and keep it, for backup.

As far as the 4.8 running poorly, it could be wires, plugs, maybe a bad coil pack, etc.... Or you could just start your 5.3 swap!

I swapped in the vette servo. . . definately the cheapest and most productive mod ever, 12 bucks, 15 minutes. done. i fixed my problem with the rough idle, and i think i have even worse problems now. I ripped the dumps off my 2-out flows and ran dual tailpipes and turned them out behind the rear wheels, smoothed everything out, only problem is, back pressure problems mean valve problems. and i do have one cylinder that is particualrly noisy. as far as the tune, i just want to get another similar ECM, so when i do the swap, i'll have a programmed box already, and i don't have to sweat driving the 5.3l on the 4.8L calibration. and for 34 bucks for an ECM, i can get it and send it to nelson, and avoid hte core charge all together.

[molitor]

And the 5.3l is still miles away, needs main, cam, and rod bearings, still trying to find flat topped pistons (thinking of using 4.8l cast pistons). need moly rings, block needs to be honed, and heads need to be worked over. so far i have:

ls6 cam- cstm 112LSA
2004 5.3L longblock
stock heads
stock valves
ls6 springs
boosted oil pump
ported water pump
1.75 ratio rkrs
comp cams 7.4 pushrods(ls6 cam is gonna screw that up i'm afraid) base circle**
and waiting on OBX stainless shortys

check this out! all this so far has cost me. . . $865.73
not too shabby eh?