I just put new heads and intake onto my '88 engine and it seems to be going well so I'm thinking I'll put a cam into it. It's a truck motor, a roller compatible block but originally equipped with a flat tappet setup. The cam I'd like to use is one of the type that is designed for the pre '87 motors. Just because I have it, a lifter set and timing chain, it's paid for. It's a Comp 252H. The Comp catalog sez it will go in with the "appropriate timing chain". I'm assuming that the appropriate timing chain means the one originally designed to fit the cam and not the block. Am I correct about that? Is there anything special I ought to know other than the basic cam install stuff?

Thanks for helping out

 

You're right.

The roller cams have a ridge on the outside of the front journal to allow them to be held in with a retaining plate. By doing that, the bolt pattern had to be reduced, kinda like a 1 pc rear main crank. That's why you have to have the right 'sprocket' when using either a roller cam or a flat tappet.

If you already have a flat tappet cam, then you can swap the timing chain, as long as it doesn't have a lot of miles on it. If so, spend $30 and get a new set.

 

Do the flat tappet cams that are used in the '87 and later blocks have the same ridge machined into them and do they use the retaining plate? And what am I supposed to do with the retaining plate if I put in a cam that doesn't have the ridge cut into it?
Since the thrust surface for the camshaft is on the back of the timing sprocket, wouldn't that mean that the block would be machined down where the timing sprocket makes contact?
I already have a matched cam, lifter and timing chain set.
I'm hoping to avoid taking the thing apart and finding out that I need more parts.
Bear with me, I'm still a little bit confused (I'm sure it's obvious)
Thanks

 

I know these questions aren't directed toward me, but I'll answer them.

No the flat lifter cams don't have the step. They don't need one to hold it in the block. The angle on the cam lobes do that.

If you have a flat lifter cam in the engine now, then you don't have to worry about it. Being a stock truck engine, you don't have a roller cam from the factory, and you don't have the retainer.

No. The only difference is the groove in the cam. The retainer doesn't stick out any farther than the face of the cam. The groove allows it to sit so the face of the cam and the retainer are flush with each other.

If your engine is stock, then you'll be fine with what you have. If someone before you changed to a roller cam, then the only other parts you'll need are pushrods. The ones for the roller lifters are shorter in length since the roller lifters are taller.

That's the only other thing you'll have to change if there's a roller cam in there now.

 

Thanks,
Everyone tells me that my parts will work but I'm having a hard time picturing how it's all gonna fit together cause I've never actually seen what's under the timing cover of the '87 up block.
It is equipped with a flat tappet cam at this time.
I'll just go for it and let it be a surprise.