Yeah you do have a point but theres one more thing to think about. If you don't want 2.00 intake valves then theres one more option you can cross off and move onto to the next. I have a burnt up 5.3 (LM7 and 862 cast on heads) and heads in my garage I would sell you for like 400 bucks plus the cost of shipping. i was gonna do a rebuild but I was out of work for over 4 months so i have a debts to pay off now. PM me if your interested.

 

ok so i have been on PT for a while now and see that the popular thing to do is put in a 6L and cam it, and perhaps some type of FI. But has anyone put a bigger motor in it, like a 502 or something like that? Would a big block motor fit, or be worth it?

 

Be carefull with a Burnt up motor like that... I have 2 of them. On one motor, 2 of the valve seats actually dropped out on one of the heads and the other motor even though it doesnt look like it got hot the corrosion in the 1 cumbustion chamber makes me question how good it will be after a cleaning... Not to mention Heat will aneal the aluminum makeing them soft... Sure any thing can be fixed But how much extra $$$ ar you going to spend on it... I just sent a set of heads out that were take offs... I figured the looked real good even though they spent a little time out side. But I got a call and was told to send another Head to replace it because after a cleaning it reveled damage to one of the seats and the surrounding aluminum.... This was not visible under the carbon build up...

 

To be honest with ya I'm infatuated with the idea of my 5.3 heads on a 6.0 block(prolly and LQ4) but I wonder if there's really a discernable difference between a punched our 5.3(3.90") vs. the 6.0(4.00") from a SOTP perspective...............

 

Ouch that sucks. This one has a burnt up #8 piston ring. The block will need machining definately and the heads were fine they're just clogged with carbon build up. The engine sat under neath a barn for about 2 years outside uncovered so everything will need to be sent off to a machine shop and given a once over. I was offering it to him or anyone for sale. I'd be more than glad to take 200 for everything plus shipping. It was given to me by a friend so I paid nothing for it.

 

Probally not Much. Just remeber you will have to re-work the 5.3 heads. In stock form, They have a 1.89 Intake valve vs. the 2.0 in the 6.0L

 

That bigger bore alone will get you some good gains.... Get your 5.3 heads cleaned up and put on a solid 6L shortblock with a nice cam, reuse your intake and you've got a nice runner on your hands

 

That was inda the whole idea, keeping the little valves and now, in peace acquiring the right parts; LS6 Yellow valve springs, decent pushrods, roller rocker arms- if that's worth bothering with and some LS1 pistons...........

 

if it makes you feel any better, there are plenty of people on here, with mildly modded 6.0 swapped into ecsb, and rcsb getting 20mpg on the highway.

 

Not that it makes me feel beter or worse, I just find it hard to justify tossing a perfectly good block for womething as good as or worse. And above all else, I wanna hang on to my 5.3 heads, so more and more I'm thinking that punching out the 5.3 is the hot ticket. BTW- am I gonna need larger injectors after haning enlarged the cylinders by .120"........................