235 Main Bearing Cap Bolts

[59_PU_3200]

I noticed that the main bearing cap bolts on my 59 235 engine have two different style of markings on them. Just wondering if it makes any difference as to which ones go where. Thanks Dave

[Deve]

Could be somewhere along the line one of the bolts got changed out for another brand would be my guess. No, both bolts need to be the same grade and tensile strength. There are bolt charts on the internet that show how to decipher those bolts (markings on the head) to determine if they are the same. If they are different, go with the higher grade and replace the lower grade one. It's your engine and being careful counts. Good catch!

[59_PU_3200]

Thanks for you response. If you look at the your pictures of removing the crankshaft from the 1959 235 engine, my bolts have the same markings as you show on the two intermediate main bearing bolt heads. These markings are different than the grade markings on bolts from the hardware store. Also I have two 1959 235 engines and both have a mix of main bearing bolt markings. All of the bolts in my engine have shoulders that help position the main bearing caps. Right now I am thinking these were installed at the factory. Do you know of a source for replacement main bearing bolts? Have though about getting the ARP Stud kit.

[Deve]

I do not know of a person who sells used bolts for that purpose. The main reason for that is that bolts stretch when torqued down, so its not ideal. ARP is a good choice in my opinion. McMaster.com may sell the correct bolt/grade/size/length. I use them a lot.