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Blue Rat · 04-07-2014, 08:39 PM

Velocity is more important when it comes to head flow numbers. If you do the 461 go with the 270cc heads. If you go with the 489 I would go with 270cc to 300cc heads. I would stay with oval port for better flow if it was me. The solid roller would make some good numbers. But it has to be right on the camshaft. You also need a lot better parts combo too. Need better valves. Be sure a pick some pressure fed lifters. Your valve spring pressure is going to be a lot higher too. Head Studs an good rocker arms an push rods are a must with a solid roller. Don't forget about the stud girdle.

Don't forget about those expensive head gaskets with aluminum heads.

04-07-2014, 08:39 PM	#33
Blue Rat Registered User Join Date: Dec 2010 Location: Arkansas Posts: 608	Re: Another 489bbc question Velocity is more important when it comes to head flow numbers. If you do the 461 go with the 270cc heads. If you go with the 489 I would go with 270cc to 300cc heads. I would stay with oval port for better flow if it was me. The solid roller would make some good numbers. But it has to be right on the camshaft. You also need a lot better parts combo too. Need better valves. Be sure a pick some pressure fed lifters. Your valve spring pressure is going to be a lot higher too. Head Studs an good rocker arms an push rods are a must with a solid roller. Don't forget about the stud girdle. Don't forget about those expensive head gaskets with aluminum heads.