Flathead Headbolts

I just removed the aluminum heads from my flathead sprintcar motor after almost 20 years. After drilling out 4 bolts due to corrosion of the aluminum in the bolt holes the heads came off. These Offenhauser heads were used and reconditioned whe the engine was ***embeled in mid 80's with bolts from 49-53 ford. Due to the corrosion, I would like to replace them with new bolts. Does anyone know of a source for new bolts. I have looked in ARP catalog online but nothing showed. These bolts have to be the long bolts used on late flatheads due to the alum head thickness.Edlebrock doesn't list bolts for their heads. Any help?
deChrome

 

Try Motor City Flathead, I purchased the ones I needed from them several years ago.

 

I used a stud kit from Speedway on my Offy heads. $100 well spent.