I have a 87 Suburban 350. This is the second truck 350 I've had so I know what's going to be under the intake. The lifter walls are higher and the ***** are there in the middle of the lifter valley for the spider assembly to rest on. But they didn't drill the bolt holes there from factory. They installed regular flat tappet cams in these. I was wondering if this is that hard to drill without messing up?

I am considering putting this in my Iroc after new crank bearings and a clean up. I was hoping to put a roller cam in.

 

you don't need that for retrofit lifters. Just get a retrofit setup and you'll be good to go. You can use the new style roller cam if you change the timing gear set, at least that's my understanding. If you don't, you'll have to use the "retrofit" hydraulic roller cams.

 

Are you sure they are not drilled/tapped?

The block I got for my engine was supposedly out of a newer truck, it's a 4 bolt block... but it had the holes in the "*****" in the intake valley already drilled and tapped.

 

I don't know if they are on this specific block. The other 350 I worked on was from a 87 TBI Truck and they weren't drilled/tapped.

91Z28, I am on a budget and plan to use the stock retaining stuff. I already have the lifters. (If my brother didn't misplace them in his garage. I had them soaking in oil.

 

The block from my '88 truck wasn't drilled/tapped either.
My plan was to swap to a factory hyd roller setup which I pieced together using ebay and take off parts.
I plan on drilling and tapping the holes using hand tools. There isn't that much stress on any of the parts that absolute precision is needed. But if you're unsure of yourself, trying out a few test holes on a scrap block or head is a good idea. Broken taps are a pain.

Also, start with the correct size drills for the taps you'll be using, be sure everything is sharp. Don't forget the cam retaining plate either.

 

Is the cam retainer face machined & drilled/tapped?

 

I think so. Not sure though. I didn't have the timing cover off on the last motor I had.