Well im stuck- i wanna swap out the 4.3L for something bigger that has 8 cylinders..... im leaning towards an LT1 or a 5.3L vortec- Can those 5.3L really put down some good #'s on stock bottom end or do they need a rebuild as well- My goal is 500hp w/ boost......

(if i go LT1- rebuilt bottom end- forged rods/pistons/ cryotreated crank/ Garret large trim turbo/ turbonetics BOV and 50mm wastegate/hallman Boost controller/ 72cc heads/ 9:1 compression)

 

I think if you are choosing between a Gen II and a Gen III as a base to start with - go with the Gen III.

 

Hell yah!!!

 

so 5.3L?....... do i need to build up the block if i want to run boost? What is the compression ratio?

 

Well, I think I'm going to speak for all of us...how are you going to use the vehicle???(i.e.street-strip) How much boost do you want to run, whats your budget and what is your intention for the vehicle?? There are so many questions and answers on this sudject. This is truely a loaded question. But on the flip side, I like to see a sbc run with a bbc. I think that it's cool as !You'll get more responces up soon and then flooded with many dilemmas!! The comp ratio is 9.5:1 on a stock block.

 

Personally, if I was gonna go through the trouble of swapping out a V6 for a V8, I'd go straight to a 6.0 (if funds allowed of course). But even just going to a 5.3 there's alot that you can do.

 

Go with a 6.0. But to answer your question, yes, a stock 5.3 can handle boost, how much is to be determined lol

 

My stock 5.3L did well over 500rwhp for awhile till I sucked up water. When we tore it apart it looked brand new with no signs of stress. WEe never dynod it but on 14psi and doing the math from my MPH and weight it calcs out to over 550rwhp.

 

Go With The 6000 Vortec.

 

That is very impressive I WILL say!! On a stock bottom end???