Looking for a "reasonably priced" bolt on set of BBO heads to change from my 4a heads on 403. Want to see how much power I will gain from the swap. Large valves a plus. I do need to know cc specs to determine compression ratio since I will be running with Arias flat tops.

 

Get with Brian Trick 507olds.

 

You will also need an intake, like an Edelbrock Performer RPM, that has the extra material to match the bigger ports of the big block heads.

 

I already have a performer intake that has been matched for the BB heads. The heads is the last step for me to see what difference this combo makes.