Can i use roller cam parts in 81 block.

[WarHorse66]

Hi I'm new to posting here. But my question is about the fitment of 1990s roller cam and lifters in a 1981 block. I know eww 1981 block, but it's what I have to work with and another engine isn't in the budget. I'm just wondering if I can use the later model roller lifters and camshaft in my block. I realize I would have to have my machine shop drill and tap holes for the "spider" to keep the lifters in place, but is that all it would take to make this feasible? Or am I just being nieve and I would have to purchase a roller conversion kit from an aftermarket source like comp cams?

 

[Steel1]

You could have the valley drilled and tapped for the spider tray and then use roller lifters or
you could use a set of link bar lifters. No tapping of the valley is required with the link bars.

 

[General karthief]

You could have the valley drilled and tapped for the spider tray and then use roller lifters or

Ahhh, but is this true? After some googlefu that I did awhile back the answer is yes and no. Clear as mud.
Lets start with NO: (because it will help with understanding the YES)
NO: the non-roller block is not drilled for the spider that holds the dog bones that keep the lifters from rotating.
YES: you can have the block drilled and tapped for the spider but (and there it is!!) what about the dog bones? I have read that some have experienced problems with the placement of the bones and excessive wear on the lifter that resulted in failure. So this is a maybe?
NO: the lifter bores of a non-roller block are not as tall, a roller lifter is taller than a flat base lifter, this makes the lifter misaligned with the oil hole that feeds the lifter and you can guess the results when that happens.
YES: there are cam companies that make a 'small base circle' cam that will lower the lifter in the bore so the oil holes align to feed the lifter properly. But (there it is again) you have limited choices and can be expensive.
So, there it is in a nutshell. A muddy nutshell.
Of course the right way is to pony up for the link bar lifters, compared to retrofitting roller lifters into a non roller block is the correct way to go.
DISCLAIMER: this is from research done years ago when I had this question in my head and not based on any actual experience real or imagined.
Would I do the retro fit? NO
A flat tappet setup can live a long life if done correctly.

 

[Steel1]

When I built my 393w with a 69 block my machinist offered me the option of having the valley drilled and tapped or going link bars.
I've seen people posting about different roller lifter body lengths (seems unclear though), so measuring/selecting the correct lifter height in that case would be crucial.
I chose to go with link bars only because it was my preference so never needed to look into lifter height.
But you bring up a good point karthief.