[Xavier]

I have the 3/8" 12pts on mine. I used 3 different wrenches (don't destroy your good ones). One was cut in half as a stubby, nothing else was changed. Another had the rounded area on the closed side grounded really, really thin (still was able to torque it down quite well). The tips of the open area were significantly reduced, probably in half. The last one I made the closed "O" into a "U" on the closed side of the wrench. These (3) wrenches and about 20 minutes total did the trick easily. The Chinese wreches were about $5.

That did it, and could not have been done without it. Nothing else would do it. But it HAD to be the 3/8 12pt (ARP), NOT the 7/16 sold by Spectre - they are just too large and rub against the pipe. No way to get the wrench around it.

Bolts which work on an FE maybe chalenging for small block and vise versa. Pipe size also has to be taken into consideration, so asking about what header bolt to use (which you did not ask) is like asking "what is the best kit car to buy?".

Thats my two cents. Good luck.