I am rebuilding a 27 motor that will have a Fronty S head. Which road cap bolts are best to use, the original castleatted type or newer self locking type. Are any of the self lockers better than others?
I use ordinary grade 8 nuts, Loktite, and a torque wrench!! Have for years
Chevy 350 rod bolts work nicely and you could use the lock nuts supplied with them after you get the rods fitted. There are longitudinal serrations on the shank you may need to smooth out. If you want to use castle nuts then you can drill cotter pin holes in the bolts. I would not use the original Ford rod bolts unless the tooth fairy brought you a set of NOS ones.
Ted has a point about using original rod bolts. So many of them have pulled threads from being strong armed to line up with the cotter pin hole. If the slot can't be lined up at around 35FLBS then swap the nuts around.
On a Model A that gets set to the same torque I had to brace myself and use a cheater bar to remove the nuts. The threads on the rod bolts/studs were toast, with a model A rod if the threads are toast so is the rod, they are forged as part of the rod. At least with a Model T you can use the Chev 350 fasteners.
And yes I just buy new grade 8 3/8"bolts and grind a flat side on the head
I use the Chevy small block rod bolts and nuts. They work great, and are free if you know a rebuilder. Dave