metcalfm45

Alright so I spun a cam bearing the other day in my 5.3l. Found the bearing laying on top of my crankshaft today when I dropped the pan. So I'm pulling it to build a 6.0l. Now with this 6.0 I'm going to port and polish some 5.3 706 heads with bigger valves dropped in it as well. With diamond pistons and eagle h-beam rods. What cam would yall recommend to get max performance out of that motor. I'm shooting for all of 400+ to the ground. Pretty reasonable number there.

low2001gmc

iTrader: (148)

A 228 232 cam would easily get you there. However, beware that castech 706 heads are prone to cracking so i wouldnt invest in them...too risky...

HCI2000SS

iTrader: (2)

I'm running a forged 6.0 with diamond pistons and I - beam rods. PRC 5.3 heads (862's) and a cam almost identical to the MS3 cam. I also have 4.10 gears and a 6-speed trans. For me this combo works great

c u in rearveiw

Tq/hp?

Tuskyz28

If I was you I'll sell those 5.3 heads. Not bashing those heads but about time you pay for a port n polish (job) you could had dawn near bought a pair of L92/LS3 heads and get you a small cam to match them and easily achieve your goal. I would do a cam 225/236 or so... should easily put you around the 450 mark.

xdanny510x

When i had my 5.3 in my silveraso with a small baby 224/224 cam i pushed 380rwhp and 367rwtq . i had milled 706 and long tubes and true dual exhaust.. So now that u wanna so a 6.0 u shouldnt have no problems reachin that number

metcalfm45

Sorry I'm late on the reply guys. I'm going with a 232/234 cam in it. I'm running into an issue with the build. I'm having clearance issue with this Gen IV motor and the Gen III 5.3L heads. Heads are untouched as far as milling goes. When the heads are set in place the motor turns fine. (No rockers attached) when I put the head bolts in, and run up by hand til they quit turning, the motor won't turn. Acts like the piston is hitting the head. Not a cool situation to have. Any suggestions? Or any experience with this? Any experience with a new Gen swap to replace a Gen III motor?

LLLosingit

iTrader: (4)

What head gaskets are you using?
Are you using domed pistons?

metcalfm45

Stock height felpro gaskets, though they are for the Gen III...not sure if it'll make a difference. And stock pistons out of a Gen IV 6.0L

LLLosingit

iTrader: (4)

Are they for the larger 6.0 bore or the 5.3?
The pistons have to be hitting something and I don't see stock pistons coming that far above deck height to hit the head but I could see them hitting the gasket if it were smaller 5.3 bore.