Which car parts to scavange 7/16" factory bolts?

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The Artist formerly known as Turbo84
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Clinging to my guns and religion in KCMO.
I'm getting close to putting the (lighter weight) C4 batwing on the '69 rear end, but I need some cover bolts to complete things (the stock C3 cover bolts are too short). I'm looking for some factory 7/16" bolts, preferably 1 3/4" long, but I can probably do with a combination of 1 1/2 inch to 2 inch (and shorten the longer bolts). I like the stock look of factory bolts versus something from the local hardware store. I'm just going to go looking through stuff at the junkyard sometime, but if anyone has any recommendations for what parts of the car are more likely have this size I'd appreciate the info.

Thanks.
 
I have a chart somewhere that has GM bolts that are available from Paragon. Are the original bolts that were used on the C4 washer head bolts (because of the aluminum)? Also seen a mix of 7/16-14 and 7/16-20 used.
 
I kind of luck out in that I have a large ACE HARDWARE store down the street, and their nutz and boltz department FAR exceeds any other store I know of, except the one I worked at as a kid who was easily impressed.....:shocking:
 
I've done a fair share of 80-82 diff conversions to iron, pretty much what you're going to do with the C4 cover and 69 iron diff. Personally I would keep the iron cover on the iron diff but when I do the conversion, since the iron units are better then any 80-82 diff, I use 271 Loctite and Nord Lock washers with hex or socket heads. The expansion difference between the iron and aluminum will cause an oil leak most likely otherwise. The iron cover holes are 7/16-14. The socket heads are stronger.
 
I've done a fair share of 80-82 diff conversions to iron, pretty much what you're going to do with the C4 cover and 69 iron diff. Personally I would keep the iron cover on the iron diff but when I do the conversion, since the iron units are better then any 80-82 diff, I use 271 Loctite and Nord Lock washers with hex or socket heads. The expansion difference between the iron and aluminum will cause an oil leak most likely otherwise. The iron cover holes are 7/16-14. The socket heads are stronger.

I currently have the late C3 batwing on the car (with the iron rear end). Haven't had any lube leak issues. I'm swapping to the C4 batwing to pull more weight off the car. The C3 batwing pulled 15# off the car compared to the iron cover and steel crossmember. The C4 part should pull an additional six pounds off the car.
 
Larry and Gene, your posts got me thinking. Yeah, I need the washer head type bolts (a bit harder to find in the junkyard), and while waiting to get an opportunity to get over to my favorite junkyard I stopped at a large hardware store in the area and looked around. They had some washer head bolts that look good and would work in the mean time, but I wasn't thrilled about their prices. Then I remembered TT telling me about McMaster Carr. I ordered some bolts from them, and they'll do the job quite well for now. (If in the future I start getting nervous about losing too many NCRS concourse points for using non GM bolts on my car, I'll cancel my other activities and start actively scouring the local junkyards for the "correct" bolts.)

Thanks guys.
 
Mcmaster is unbelievable. If I order before 4PM, I will get my delivery the next day, regular UPS ground.
 
I used them all the time at work for that purpose. McMaster Carr can get you fixed up in a pinch. Not always the best price, but for availability and variety for all the odds and ends projects I can get into at work and home, they are unmatched.
 
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