I have a Y pipe off of an Olds 215 and the headpipes measure 1.6 inches. I'm thinking the 300 Y pipe might be the same. Anyone know for sure what size the 64 300 pipes are?
Here is what I got. Olds 215 manifolds.. 3 inch Bolt spacing. Donut area od 2 inches ID of outlet 1.5 inches. 64 Buick 300 manifolds. 3.5 inch bolt spacing Donut area OD 2.25 inches. I'D of outlet 1.75 inches. So would the stock 300 headpipes have been 1.75 inches ID?
OK..Just got verification from someone with a stock 300 in a 65 Skylark...They are 1.75 inch. The Mufflers I have are 2 inch so I'll have to figure out with the exhaust guy how to transition. I'll also have to try to locate the proper size and style of clamp to bolt the pipe to the manifolds
