protraveler

2001 GMC Sierra 4.8 L. Has run great for almost 300k miles on 4x4 Z71 . Looking to rebuild before it starts to have issues..Would like more torque, don't need high revs..Its a truck engine..
I know 4.8/5.3 is the exact same block, different is only stroke..
I want to replace crank with 5.3 and new connecting rods.. Want to keep the 4.8 pistons to benefit higher compression. Keep same heads, but bigger cam and ported and polished existing heads..
Can I use same reluctor wheel? Will computer need reflash? What about fuel injectors? Anyone had experience with this project, appreciate your advise so save any potential pitfalls. Thanks in advance.

FFDP

iTrader: (2)

Same reluctor wheel, nothing changes there.

Yes it must be custom tune, no way around that.

Consider 31lb/hr 8.1 vortec injectors, the stock 24lb/hr injectors do not go very far on cammed engines. So it's easier to spend the $80-100 on some used stock injector and not have to worry about it.

protraveler

Thanks for the info.
Your recommendation about higher flow injectors sound like reasonable plan considering better breathing and an increase in volume. With that in mind, do you think I should plan on going for larger throttle body?
Ive heard that the fairly long runners on the stock composite intake manifold aren’t bad for making torque...what do you think?
thanks again for the information

FFDP

iTrader: (2)

The truck intakes are great the torque, it's exactly what you want in a truck.

With just a mild setup like you want to do, a larger throttle body isn't needed. The engine won't be at the point of out flowing it.