Thats what I though the belt would give way before any damage was done to the crank
I was going to run it off the double idler pulley by welding these two together
This also will allow the belt to slip on the smooth pulley in the event of a back fire
Here a quote from the l67 forum have you heared of this before -
"Also, watch out with gilmer drive on an L67. If the engine backfires, it is possible that you could break something, like your crank unless you fit a burst plate to the LIM. The reason being, is that the backfire wo'nt have anywhere to go due to the sealing of the blower and it forcing air in. As the air has to go somewhere, it will try and go up into the blower, possibly momentarily locking the blower up. The gilmer belt isn't going to stop and the weakest link is the crank. I haven't seen this happen, but I know it can happen on 308s. So just be careful."