Engine Drilled for 1/2" headbolts
- Thread starter rockyracoon
- Start date
You’ve already got the studs in place, so this may not help. ARP makes head bolts with 1/2” shoulders for that application.
Bill
If you do not use the bolts with the 1/2” shoulders like Bill suggests, I wonder if ARP has spacers (or tubes) for studs in this case.
Edit: Sleeve is the word I was looking for.
Edit: Sleeve is the word I was looking for.
Last edited:
They may be cheaper elsewhere or maybe other manufacturers (like arp) but I think this is what you need.
- Mar 2, 2015
- 6,945
- 5,816
- 213
I always tapped my blocks for 1/2 studs. You would have to be really careful with shavings. Bushings work though. The 1/2 studs give more clamping force. All my blocks had them but my current engine builder left this one 7/16ths.
I had a set of ported e7 heads on my 306 and 347. They actually worked pretty good on the street. Didnt flow as well on the stroker. The exhaust side is where most of the power loss comes from. The heads were shaved a little bit to bring the compression up. I didn't have stock pistons.
If you turn the heads upside down, and use a baby medicine syringe, you can measure the chamber cc. Best to do it now while they are off. Just fill with water to the top cc line and fill the chamber until its level all the way around. Subtract the amount left in the syringe from the full number and you have a starting point to get a real compression number. Compression is important so you know what gas you need to run. You'll also need to bring the cylinder up to top dead center and measure piston bore depth. Then calculate ( or find ) your head gasket installed thickness.
I had a set of ported e7 heads on my 306 and 347. They actually worked pretty good on the street. Didnt flow as well on the stroker. The exhaust side is where most of the power loss comes from. The heads were shaved a little bit to bring the compression up. I didn't have stock pistons.
If you turn the heads upside down, and use a baby medicine syringe, you can measure the chamber cc. Best to do it now while they are off. Just fill with water to the top cc line and fill the chamber until its level all the way around. Subtract the amount left in the syringe from the full number and you have a starting point to get a real compression number. Compression is important so you know what gas you need to run. You'll also need to bring the cylinder up to top dead center and measure piston bore depth. Then calculate ( or find ) your head gasket installed thickness.
Similar threads
