Just got a call from the machine shop and my one of my 049 heads I took to have rebuilt came up with a pin hole in the intake chamber when pressure tested. They have a 781 head they are willing to sell me. Is it ok to mis-match these heads if they cc out the same? What if they are off a few cc's, will that cause any problems?

Welcome to Team Chevelle.
First post I see.....

Functionally there is little to choose between the two heads....very similar. Both heads chamber volumes vary widely....

Down the road, if you sell the engine, you will get the same question you are asking us here. Maybe a team member near you has a single head so you can make a matched set.....

Pinhole in the chamber??????? odd....very odd.....

My mechanic friend thought it odd as well. The shop pressure tested it and found the small pinhole 1/4 " below the valve opening. He said at 25#'s of pressure they got a little bubble out of it. He said there was previous leakage and that's why it was pressure tested. It is so small a thin piece of wire will not go in the hole. Could be a casting flaw that gets bigger as it gets hot? Beats me.

hmpf. if they sell you their 781 then will the next guy get sold your 049? I'd have it checked again somewhere else. Not that I'm suspicious or anything.....

I was thinking the same thing......possible scam!

I really don't think these guys would scam me. They have done work for me before and have been honest with me. I see that cracks can be fixed with stitch pins, do you think this is possible with a pinhole?

ask to see it bubbling. could be leaking around a valve guide if somebody changed out the cast iron guides.

pinholes can be fixed, but you need to be able to get to it with a drill.

Where did the heads come from? Did you get them off a running engine?

There's a set of 781's on e-bay. Current bid is $50.

http://cgi.ebay.com/ebaymotors/Chevy-454-Heads-Matching-Numbers-BBC_W0QQitemZ110251926182QQihZ001QQcategoryZ33617Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem