Type of cam in stock '89 chevy 350 motor?

[lha1992]

I was just wondering of type of cam that is in my 1989 chevy silverado 1/2ton? Its a 350 K-code motor, all stock, nothing has ever been done to the motor. Same motor since it was new.

Is it a roller cam, flat-tappet, etc? I'm just wondering is all. Thinking of later on down the road of what updates I could do to the motor.

Thanks

[bwood]

It should be a hydraulic flat tappet cam. The block is roller cam capable, but you need the cam and lifters of course, but you also need the 8 lifter plates, 1 lifter plate retainer, 1 cam plate and the bolts for them all.

[lha1992]

So it is a hydraullic flat-tappet cam? Does that mean also that I need to run oil that has enough zinc or ZDDP in it or does that only apply to the older trucks from the 60s and 70s?

And thats good its roller cam capable. So I could go with some Comp Cam if I wanted to right? But then that brings up the TBI which i've heard does not like big cams.

[89chevsj]

tbi doesnt like BIG cams but you can put a bigger cam in it. yes it can be expensive but it really makes an improvement. especially if your trying to builld a sleeper outta "PAW PAWS truck"

[lha1992]

Yeah, thats what I thought after reading all the threads here haha. But yeah, i'm just getting ideas for later down the road for Paw Paws truck. As you said, i'm thinking of makin a sleeper out of it. Looks stock but has something hiding underneath the hood

Other than the worn valve guides where it will give the chevy salute when it hasn't been started up in a few days the engine runs great! As ya'll say, drive it, take care of it and when something breaks fix it.

[89chevsj]

I'm sure someone will tell you the specs for camming it. i always liked sleepers haha. is why i always buy them. i would start out with a new exhaust (duals) headers and see where that will get ya.

[Orangette]

88-95 trucks came with Flat-Tappet cams, SOMETIMES the block is roller capable, but not ALWAYS.

96+ Got roller cams.

TBI does not like big cams, if your thinking your gonna get a low LSA cam with a rough idle to run proper in a TBI 350, forget it.

[89chevsj]

guess i got lucky. of course mine is a very strange set up thatI dont even know everything about yet.

[motovate]

I know this is an OLD thread - but maybe some one who knows can give me an answer. I understand TBI engines don't like bigger cams - but is it the TBI itself not the engine itself?? In other words if I take a running TBI engine in a 1989 Chevy Suburban- pull the TBI, manifold, distributer, cam and do away with the computerthen replace with an Edelbrock Performer carb, manifold, cam, external wired fuel pump and HEI dist will it run like an non TBI engine????

It would seem it should.

Thanks.

LBM

[BigBlocksRule]

TBI computers are vacuum sensitive, so a cam with much less lobe separation angle won't work well with the computer. The '96 up multiport injection can handle a lot more since it measures engine load and airflow differently.
The block itself is capable of a good bit more power than the TBI can provide.

[motovate]

Thanks - that makes sense.

LBM

Originally Posted by BigBlocksRule

TBI computers are vacuum sensitive, so a cam with much less lobe separation angle won't work well with the computer. The '96 up multiport injection can handle a lot more since it measures engine load and airflow differently.
The block itself is capable of a good bit more power than the TBI can provide.