I know its written that the 250 is shorter, and the 216 was missing from my truck when I bought it, but it sure seems to me its longer. I cut the firewall for some clearance and had to move the radiator forward to keep the fan from hitting, so thats what I go off of.
It is great little engine with plenty of power, its easy to work on and parts are easy to come by. If the older bell housing has ears to mount it, then front mounts would be a piece of cake to make.
Joe
