Looking for advice on engine upgrades

[E.D.75GMC]

I'm looking to get more power out of truck. It's a 1975 GMC 3/4 ton with the original 350 4bbl (has 4-bolt mains) and TH350. As it sits now it's in excellent running condition with no leaks, and the inside of the engine is very clean and it makes no noise. I have a set of SBC headers hanging in my garage that came with an 81 Blazer I used to own. I've been mulling over putting the headers on, and while I'm at it I may as well do an intake manifold as well as a cam and lifter kit. Wondering what people's opinions are on good parts to order. I did the timing chain and gear set back in August. Also, the carb that is currently on it is a rebuilt quadrajet that's only 16 months old so preferably I would like to keep that carb.

[Edahall]

You might add to your list a set of heads such as Vortec heads.

[TwoFiftyShifter]

Great carb. Leave it. Headers and start looking at cams. Then I'd your wallet isn't too light, Vortec or equivalent heads.

[E.D.75GMC]

Unfortunately I won't be able to swap the heads, don't have a big budget. Working part time while I'm in school currently.
Now, I don't really know much about cams. I would be having a good shop do the installs. I know what cams do but I don't know how to judge what is best for my truck. It has the 4.10 rear gears that come with the 3/4 ton so it revs pretty fast. I'm just looking for something relatively mild as the truck is just a driver. Don't know if anyone has any recommendations on a cam and lifter kit? And if I would need rocker arms as well?

[GERRYM454]

usually lack of power with a small block is a sign of cam wear. almost impossible to diagnose in early stage
my suggestion is look to a roller cam kit if replacement is needed.

next choice is go to a big block

[rich weyand]

Put in a Comp Cams 12-235-2 and new lifters. You probably should do springs as well.

Google my last name and 12-235-2 for lots of posts and discussions of this cam and close alternatives: https://www.google.com/?gws_rd=ssl#q=weyand+12-235-2

[E.D.75GMC]

Thanks Rich. I looked them over and the 12-235-2 seems like a wise choice. What kind of valve springs should be used with this?

[rich weyand]

Get the recommended lifters and springs from Comp Cams. They are documented on the 12-235-2 product specification page here: http://www.compcams.com/Company/CC/c...x?csid=95&sb=2

Also, be very careful to follow lubing instructions during assembly (Comp Cams has an assembly lube), follow the correct break-in procedure (from here for example: https://www.chevrolet.com/content/da...e-12499529.pdf), use break-in oil during break-in (I think Comp Cams has that as well), and use a ZDDP additive in the oil after break-in. I run Mobil1 10W30 with half a bottle of ZDDPPlus per oil change, for example, but there are at least as many oil recommendations on this forum as there are forum members.

You probably also want to change the timing gears and chain while you are in there. You have to take most of that apart anyway. Why put the old ones back on?

You can either pull the engine to do this job, or do it in place. If doing it in place, take out the radiator, shroud, grill. Doing it in place is about a day and a half for a trained mechanic, with another person to help you get the hood off and on. Everything else is a one-man job.