Need advice on engine upgrades please

[Nick2000]

I have a 2000 Sierra 1500 4wd SLT 5.3 (not sure if it matters but the more info the better). I currently have an oil leak coming from oil pressure sending unit and have also been consistently losing coolant. 
 

I am looking to upgrade my engine while replacing this unit. Is there anything else I should replace while I have my intake manifold off. I have been looking into cams and other things but not sure what I should do I just want more power honestly and need some advice from people who know things. (no I’m not taking the lift and tires off lmao)
 

Things I have done to the truck:

-6 inch suspension lift/3 inch body(was on it when I bought it)

-37” Toyo Open Country MT(downsizing to 35s within the next year)

-4.56 gears front and rear

-4l60e rebuilt with “best” parts allegedly

[CamGTP]

Do you have a budget and how much power do you want to add??

 

Those are your two biggest questions to answer.

 

You can easily add 50+hp for under $1,000 with simple mods.

 

I highly suggest a small camshaft upgrade, stay with a 212/218 or smaller in size to run the same stall torque converter you already have. I'd probably put in larger injectors from a 8.1 truck or a L33 flex fuel truck. Those injectors are cheap and give you more headroom for power.

 

Do some long tube headers and then get it tuned. That alone should add at least 50hp and torque to that engine and make it much quicker and fun to drive. Keep the stock intake manifold, keep the stock cable throttle body and all that. You won't outflow those parts and keeps your budget down.