I ran across a good deal on a used 5.3 with 130k miles so I bought it. I plan on having the motor built here locally in April. But I'm gonna start buying the parts I need now so I don't go broke lol. I will be buying the speed pro 4.8 pistons to bump up the compression on the 5.3. I will also be buying new gaskets for it. I will be using the truck intake and the 862 heads. The motor will be going in my 04 rcsb silverado. I've already got lt's, exhaust, tune, and 3.73s. Should I get the motor bored .20 over or keep the stock bore? The motor ran great and held a good oil pressure. And Id like some people opinions on what cam to go with.

 

I'd keep the stock bore unless you planned on doing all new internals for the motor, such as forged part and so on. Cam and the right set of heads would really wake it up, and be easy to do while the motors out instead of in the truck. But you're on the right track starting with lt's and exhaust.

 

I've wanted to do a cam swap for awhile now but didn't have time and I drive the truck everyday. So I bought another motor to build and still drive the truck. But I don't have any plans on the heads right now. Those will be later down the road. I've looked at some of the comp cams and the tsp. But can't figure out which one to order. I want a choppy idle and still have good low end power. I plan on using a 3k stall. Anybody using the tsp 220r?

 

Hard to tell you to stay standard or bore it without a machine shop checking it out first. With 130k miles, it could very well need to be bored in order for the rings to seal.

 

Ill have a machine shop check it out and order the pistons last. I've heard good about the tsp 220r and decided to go with it. Would a 3k stall be enough for the tsp220 cam?

 

Yeah, a 3k stall will be fine with that cam. What LSA do you plan to get? If you want some idle lope, might think about 112 LSA.

 

Yea I'm gonna go with a 112. With my 862 heads and the 4.8 piston's my cr would be around 10.5to1? And will I have any clearance problems with the 220 cam?

 

Yeah, about 10.5 CR with true flattop pistons. Shouldn't have clearance issues. Other people have used that same combo. Of course, you should measure to be sure. If you have to bore the block out, you could get pistons with a little bit of valve relief (if in doubt).

 

I'll be sure to check, what kinda numbers would the motor put down? I've seen with the cam swap between 290-330rwhp but don't know with the 4.8 pistons. Guess I will go ahead and buy new lifters and a timing set. Then saving for a beefed up tranny.