Are all 5.3 blocks close enough that I can buy one , build it the way I want on the bottom end and then pull mine out and put my heads and intake on it. Or will I run into any sensor positioning issues?


The engine I have currently in my 09 1500 Silverado is 4.8. I want to build a 383 turbo and am ready to buy a block to send to the machine shop.

 

Dont know it it holds true for the gen iv blocks but the 4.8/5.3 gen 3 blocks were the same.... I would assume the gen iv 5.3s all use same block..... But to answer your question yes your heads and intake will bolt up,... I have gen iv heads on a gen 3 block.....

 

Thank you very much for your fast response. I will be getting something this week.

 

Glad i could help

 

I'd get a 07+ NNBS block, because that way to holes are already there for the knock sensors. Also the cam trigger is on the front and not on the side of the block like the gen 3 motors and the 24x to 58x difference. NNBS blocks have a different looking valley too because of DoD and no knock sensors there but not sure that even matters.

 

Thought id mentioned sticking with gen iv block sorry!!!

 

So does someone make a wiring kit to attach to the wiring harness to adapt to the different placed sensors. I can buy a gen III block WAY cheaper , and I would like to limit down time on the truck or I would just use the 4.8 block that's in it.

 

The extra money you have spend on extra parts could equal out the cost of the Gen4 motor.

 

since you have a GMT900 you will need a Gen4 motor to build for it to be a direct swap

to be truthful a 383 is waste unless you just like that number, the money you spend to make a 383 you can do same for a 6.0 to become a 402 or 408

not to mention not all blocks will check out safely for boost when boring that much

 

To be honest it is mainly just because everyone seems to build a 408. and a 383 kinda gives you a nostalgic feel. My original plans were to just put a cam and head studs in my 4.8 and boost it until I talked to a shop and found out how cheap it was to throw a crank rods and pistons in it.