The 91 305 head has the round push rod guides

I was just going to use my carbide proting bits to enlarge the holes for 1.6 rr's

The guides are not a contact area due to the Self adjusting Rockeres

So I dont see the problem by just doing it by hand

Has anyone else done this? or see a problem with it ?
How much will the angle be changed ?

Thanks for any input

 

there is a drill guide made for this, then you use a hand drill with the guide, real simple and it doesn't cost much, look in comp or lunati catalog for it

 

I actually bought the Comp cams Louis Tool and it actually turned out to be for the Sloted style heads pre-89 I think

so they make two different type tools?
thanks

 

anyone else please?

I really dont mind what it looks like ...so I dont think it will be an issue as long as I make the clearance
think it's ok to do by hand

 

I think with the heads with the round pushrod holes you shouldn;t have to touch anything on them, assuming you're still using self guided rockers. Some older slot-style heads have problems, but you shouldn't.

If you're in doubt, put on the rockers and turn over the engine a few times by hand..see if the pushrods rub at all.