The B&M 144 blower atop a sbc I had in my previous street rod ('29 Ford) had no problems fitting with the radiator. There was ample room to run a 16 inch electric fan. You should not have to notch your firewall for the blower unless you have your engine set back more than normal. The 174 blower is only a little large than the 144. I did not run a hood, so cannot comment on how much space I had, but I have seen them fit under the hoods of street rods.