# Chevy head repair



## eugene13 (Sep 30, 2018)

My son and I were given a 327 Chevy as part of the deal in building the Cat Rod.  (See the thread "Rat Rod Recipe" in this forum)  When we took off the valve covers we discovered a broken stud boss on one of the heads. I neglected to get a before picture but you can see the damage in the first picture.  Our first step was to machine all the bosses down .375" in order to use guide plates and threaded in studs.  We picked up the center of the adjacent hole and moved over 1.812" to center up on the damaged hole,  then drilled tapped the hole 5/8"-11, and screwed in a 5/8" grade five bolt with lots of locktite.  After sawing off the bolt we milled off the excess, picked up the center of the adjacent hole, moved 1.812" and drilled and tapped 7/16"-14.  While we had it in the mill we tapped the remaining holes and enlarged the push rod holes to 7/16".  I wouldn't recommend this repair on a race motor, but we did do this on a friend's Demolition Derby Car, and he ran the crap out of it with no problems.  Another quality afternoon spent with my son.


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## Latinrascalrg1 (Oct 1, 2018)

Pending damage/repair those heads may be quite valuable as they appear to be the highly sought after double hump heads that should come with the larger Valve's.


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## eugene13 (Oct 1, 2018)

Latinrascalrg1 said:


> Pending damage/repair those heads may be quite valuable as they appear to be the highly sought after double hump heads that should come with the larger Valve's.


Yes, 2.02" intakes and I'm not sure what the exhausts are.


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## Latinrascalrg1 (Oct 1, 2018)

eugene13 said:


> Yes, 2.02" intakes and I'm not sure what the exhausts are.


That should be 1.60" for the exhaust


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## eugene13 (Oct 2, 2018)

You're correct, and they are a rare head, everyone wants them for their street stock.


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## Latinrascalrg1 (Oct 2, 2018)

eugene13 said:


> You're correct, and they are a rare head, everyone wants them for their street stock.


I just wanted to make sure you were AWARE of the Value of those heads! I ended up selling my set for north of $2500 but i got bombarded with "unscrupulous" Individuals wanting to take advantage of a non informed  seller and got more $200 "They are worth scrape metal" price offers.  I ended up using that cash to buy new Dart Aluminum Heads with the same (maybe slightly larger Valves) which i think was my best optuon for what i was building and they preformed as good if not better then the Chevy heads but irregardless you have a small fortune in those heads.....


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## eugene13 (Oct 3, 2018)

Thanks for the input, my son is building a rat rod and this will be the engine.


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## Latinrascalrg1 (Oct 4, 2018)

I had a rat rod of sorts in that the body was Ratty as hell but she was a sleeper with a built 327 from a 68 Corvette under the hood.  I would have kept the double hump heads if i had the choice but i needed the cash to make other repairs and i had access to the Dart Heads for what it would have cost to have the stock heads rebuilt.  It all worked out in the end but I really wanted to keep those heads with that block but you got to do what needs to be done right!

Anyway please keep us posted as the work progresses if you wouldn't mind, Id like to see the outcome.

Considering you have a mill are you planning any touchups to the head? Maybe redecking to increase the compression or a Port and polish job?


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## eugene13 (Oct 4, 2018)

My mill isn't big enough to re-surface a head, the best we can do is cut the spring seats and valve guides for seals, I think He just wants to put the engine together so we can move on to building the chassis.  I plan on posting the build as a project, perhaps I'll just continue to use this thread...we'll see.


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