On the 151 they really took a lot of metal out of the parts. Compare the 151 crank to the 153. The earlier 181 cranks are fully counterweighted and make even the 153 crank look wimpy.
My next door neighbor used to race 2.3 Fords in ministock and he said that the 2.5's as used in the s10 don't hold up. The 153 and the 181 had great reputations in midgets back before the VW/Autocrafts took over. Even today many of the latest custom midget engines use the 153/181 architecture but set up for V8 heads.
Plus I want to stay with readily available v8 bellhousing pattern Powerglide or T350 or 200-4r trannies.
