JB1

iTrader: (4)

well why do they even make a 4.8L engine if its all the same?

05colorado

Its the same with a shorter stroke crank..
basically so GM can rip off those who go the 5.3 since it doesnt cost any more to manufacture.

But on nnbs trucks there is AFT on the 5.3 so I would imagine that costs somewhat more to make... probably more marketing than anything.

JB1

iTrader: (4)

AFM is nothing....tune can eliminate that. The 5.3 is only $600 more and its not cheap to get 20hp and 30ftlbs tq....seems like a no brainer to get the 5.3 to me.

I think its marketing so they can say their truck comes standard with a V8.

05colorado

Back on topic, can anyone say whats different about the truck 243 heads and the ls6 243 heads?

I was told its only valve size, but not for sure and if so, Can we run the larger valves with the small bore motors??

zippy

As far as I know it's only the valves and springs. The size doesn't change. They still use the same size valve as the LS6.

cbenavides06

I can tell you that i have a stock 5.3 with a hypertech and i raced a 4.8 w/ cam, t.c., tuning by MTI, and a 4.10 gear and i pulled about two trucks from a dead stop and from a roll. I think it was worth the extra $600. He spent more than that on just the tuning. same body style

00SILVERADO53

I Was Told The Heads Were The Same

Phantom

iTrader: (16)

I call b.s.

trever1t

iTrader: (14)

They are the same or so WCCH has told me. 799/243 castings are identicle.