I've never been a real big fan of the vortec 454s. They just are so lazy IMO. You could do an old 454 on the cheap I bet. I see them on CL around here for a grand and lower depending on the condition. You can get holley, Fitech, or Summit throttle body EFI kits for a grand and under. You'll probably be in the $1250-$1500 depending on how you go about fuel pump and lines etc. This would be cheaper than building an engine for sure.

Every time I get into an engine rebuild, the cheap or easy and fast are out the window. It starts out with just a slight over bore, and turns into $3500 or more gone in minutes. Haha

https://www.summitracing.com/parts/sum-240500

EZ-EFI® Self Tuning Fuel Injection System (Base Kit) Fuelairspark.com

Go Street EFI 400 HP – FiTech Fuel Injection

https://www.holley.com/brands/holley...h_fuel_system/