Thedriver thank you for your thoughts as I too was considering going SB since I have a 360 block & Mancini's 4" cranks are dirt cheap at $239 & the piston/rod would be lighter as would total weight but it would still be a small big block in comparison & then I thought 440source's kits, they have a 3.915" rotating assembly with 7.1" rods which is the largest stroke & rod assy that will fit a 400 block & that will be a much more larger & powerfull eng & w alum heads/intake /water pump the weight wont be an issue.