You bet, start with a core drill, then ream, I usually freeze the guides but havent had to put any heat into the head, I also install mine with an air chisel with a bit that is a few inches long and close to the same I.D. of the guide and it has a shoulder that seats up against the top of the guide, after the guide is in and normalized ream the guide to the proper clearance. I dont know if it is the "right" way, but it has worked for me.

 

wait,do these heads have bronze guides already?if not depending on how thick the guide bosses are on the head they may need to be broken off,i know it sounds crazy but if you don't the cast will be so thin when you drill that it will flake off while the engines running.you can brake them with a regular hammer.now if your guides are that bad or do you just want bronze guides?either way whats going to locate the drill,if i was you i'd take it to a good machine shop.if you don't do it right you just ruined the head or heads and if you have porting or even studs and guide plates any extra work man you would be wasting money.
i give you credit one wanting to do this. i've done head work for 16 years and knowing what can go wrong i'd spend the money to have a shop put them in for you on a seat and guide machine cause your going to need a valve job anyway.
you'll probably or should be able to do this for less then $100 or there abouts,valve job being more.
good luck :thumbup:

 

If the head doesn't have replaceable guides, you should take it to an automotive machine shop. You need a guide and seat machined or a mill with the proper fixturing to drill and ream the heads for the false guides.

I tried it once without the G/S machine.

A long time ago........

Won't do THAT again.

tom

 

If the head doesn't have replaceable guides, you should take it to an automotive machine shop. You need a guide and seat machined or a mill with the proper fixturing to drill and ream the heads for the false guides.

I tried it once without the G/S machine.

A long time ago........

Won't do THAT again.

tom

So without the machine it can't be properly done?
The local machine shops are getting crazy with pricing, I was quoted over $500 in just labor + valves, springs, guides, etc...

I have an old Sioux valve grinder and seat grinding setup and also a quickway? set of seat cutters but I've never done guide replacement-always had a shop do that part.

 

So without the machine it can't be properly done?
The local machine shops are getting crazy with pricing, I was quoted over $500 in just labor + valves, springs, guides, etc...

I have an old Sioux valve grinder and seat grinding setup and also a quickway? set of seat cutters but I've never done guide replacement-always had a shop do that part.

you can't knurl the guides?stay a way from liners :smash:
$500 -$600 in parts and labor is about average for a good shop.
if it saves you money why not just let them put in the guides and you do the valve job?

 

you can't knurl the guides?stay a way from liners

I was under the impression that liners were far better than knurling.. Isnt knurling a "band-aid" fix that is soon rendered useless??

 

I was under the impression that liners were far better than knurling.. Isnt knurling a "band-aid" fix that is soon rendered useless??

Personally, I prefer cast iron false (.502" OD) over most other repair methods. I don't really care for phosphor-bronze liners, but I do use them in BBCs to keep the seat/guide alignment or to repair bronze guides in aftermarket heads.

I very rarely knurl any guide. Only if there is no other choice.

tom

 

the reason i don't use liners is because i've seen them move like sucked out of the guide,i don't know if they were installed wrong are what but i was tought never to use them.just my exsperiance,anyway never had a problem with knurling,i mean as long as you do not go all the way through on the intake guide.i always leave 1/8'' - 1/4'' un knurled.i'm sure everyone here has had bad exsperiances and all have a better way,just get the new guides and like tom said i would use the cast iron guides also bronze for aluminum or high performance.

 

I guess I had assumed that they had been replaced once already, if not I dont see how you can line them up without a proper fixture like tom said. Another question I guess is are you set on these heads? or would you put a different set on? there is a company on e-bay that is selling rebuilt heads with all new valves and hardware, all the surfaces are milled, they are magnafluxed and pressure tested. They sell for about $350 a pair. only thing is they are 60cc chambers like my heads are. So with a .045" head gasket and flat tops with 4 valve releifs you end up with 10:1 compression, which is what I was looking for, but you might not be.

 

Hey, thanks for all the help everybody. I think I'll just ebay off a few sets of these rebuilder heads and put the money towards some new aftermarket replacements, I'll be money ahead.