Stock bolts are 1".
I ditched the 3/4" set that came with my Mac shorty`s for 1" long header bolts.
I don`t like the 3/4" bolts and think they are too short.
1 in. or 3/4 in. will both work fine. i used the bolts that came with mine and have no problems why spend $50-$75 on header bolts.if i ever put another set on i'm going to use hex/allen bolts. i think the allen wrench will fit better in tight places.
Thanks for the input. I picked up my engine from the builder on Saturday. Right now I am using the BBK supplied bolts and the engine lift brackets were modified to fit over them. The builder suggested that I repace the four bolts that go throw the bracket. Given the "threads" about the BBK bolts, I am just going to replace them with some Stage 8 locking DHH bolts. Those will be easier to get to after its installed. Yea $50+ is a lot for 16 bolts, but its not an issue at this point. I don't want to have to worry about exhaust leaks or retorquing after a few heat cycles. If all goes well, the engine should be in before Christmas.
Found some allen head stainless steel 1" bolts for $5.00. The BBK bolts are only 3/4" and not going to work with the lift brackets. These will be easier to get to and look much better than the Stage 8. I got them from a place called Pioneer Fastners. The sell bolts for marine and street rod applications. I have to go back and get some more for hooking up the X-pipe to the headers and mufflers.
I like the 1" as well, really depends on the header and flange.
I use to pull the header bolts out and replace them with a nice grade 8 bolt and space them out so they did not hit the heads when I used the stock lift plates.