porting cost?

Duster, If you are looking for 400 horsepower, you dont need porting. You need a quality valve job like BJR mentioned. That's also a part of the cost of the machinist work. The knowledge of what it takes to get what you need. A 400 hp 360 is a good rebuild, headers, and intake and carb, and a camshaft. no porting, no solid, or solid roller, or "3/4 race" cams, or anything else you read in the magazines. Just basic good machinjing on modern equipment. The fastest wasy to being disappointed is to say "where's the cheapest..." It takees what it takes for money. If you had a good core 360, I cant se it costing more than $4500 to get a 400 hp 360 on pump gas... And none of that is for porting. If you dont have that money, adjust your plan. Dont look for the cheapest. Or you're peeing money away. I've had several bone yard 360s that ran way into the 12s even in heavier E bodies with bolt ons and a cam. So if you cant pay for a rebuild, buy some good parts, have the heads redone for performance, and run that. I bet you could be done with a bit less than half that $4500 with ease, if your engine has good oil pressure and doesnt smoke now.