I just finally got my dads old truck mint condition 1998 chevy 5.7
Going to put flomaster series 10 mufflers true duel pacesetters long tube headers what cam should i use

That depends on what you want. There are tons of cams for that engine.

Dont want a big chop i looked on summit but couldnt find anything

Call comp and convert to carb. the fuel injection on l98's sucks.

i know my buddy has same truck on 2.5 ton used as a mud truck loves the carb

I thought it was a vortec 5.7 in the trucks
or a vortec 350

It's actually an L31 by engine code. I had to look it up.

good luck getting it timed up after doing a cam engines are touchy as fuck

Having a manual, time, ability to turn a wrench, double and triple checking your work. and it shouldn't be that hard.

Don't touch anything mechanically if your just going
to wing it and eye ball shit all the time.. lol

Actually it is extremely simple if you mark everything properly. Once all the shit was moved out of the way it was a 10 min job on my bros mustang just because you want to be careful pulling and putting the cam back in.