Where did I go wrong? Other than being a cheap ***

The first motor I had in my stock weight Demon was a reringed 360 with a 280/.474 lift cam ,.430 gear and cheap GER convertor. It ran 8.0's in the 1/8, I think that is around 12.50's 1/4. It had 1 5/8 headers and 2 1/4 exhaust, Torker intake and 750 holley.