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Broken Head Bolts On A 5.3L

3K views 20 replies 9 participants last post by  Trifecta 
#1 ·
Yikes!!! I'm having a fab shop install a 5.3L in my '49 Olds. I am using Sanderson headers instead of the OEM's. The shop owner called me last Friday to tell me they had two broken header bolts in the heads They removed the broken bolts but the head got warped. He called me to tell me they had to resurface the head to make it fit flat.
This scared the hell outta me and I asked him if he shouldn't have done the same to the other head and he told me it wasn't necessary. I don't think it can be much, but it bothers me the heads are now slightly different.
Should I object and insist on resurfacing the other head or replace both heads?
Please help. I hate to pirate in on your thread, but I'm also concerned about the problem in replacing these broken holds.
Bob
 
#2 ·
Something in the air on these 5.3 . Am do the same thing instilling Sanderson header but I had a exhaust manifold bolt broke off in both heads . One out still as you can see still fighting one. But as far as yours , I guess it depend on mileage on your motor . And how much they took off your head , as you probably aware shaving head changes combustion chamber . Am like you I think I would still like the other milled down to match . Good luck keep us update on the outcome of yours. Later Jason
 
#6 ·
it is not just the 5.3. it happens on all ls engine sizes. it has to do with the high torque gm used on factory install and the locking compound they use plus the heat cycles. you typically do not see it on low mileage engines. also dollar for dollar the sanderson cast headers provide no benefit other than chassis fit and looks. some versions actually flow worse then stock manifolds. if you want performance long tube headers make a huge difference on LS engines. shorty's not so much.
 
#5 ·
did they mill the deck surface of the head or the exhaust face of the head. if it is the exhaust face then you don't need to do the other, if it is the deck face then yes the other should be done by the same amount.
 
#18 ·
This is common problem on the trucks. Its the exhaust manifolds and hanging weight of exhaust pipes as well which cause stress on the bolts as well as the AL to steel heat expansion coefficients being different. A good aftermarket bolt like ARP and no more issues.
 
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