AFR heads on 406 sbc, how much hp

[A Atwood]

What bore / stroke are you planning to run?

Most blocks come with 4.125 bore plan to use 4" arm with 6" rods

If you leave the block at 4.125, you are giving away the easiest 20 hp you could get.

I would like to know what cam specs are in the current engine. The 700/660 are just lift, and that won't make it un-streetable. High lift just kills valvetrain. Big duration is what I'm talking about.

ARN

[Orr89rocz]

Go EFI and get some of the driveability back

[mdross1]

What bore / stroke are you planning to run?

Most blocks come with 4.125 bore plan to use 4" arm with 6" rods

If you leave the block at 4.125, you are giving away the easiest 20 hp you could get.

I would like to know what cam specs are in the current engine. The 700/660 are just lift, and that won't make it un-streetable. High lift just kills valvetrain. Big duration is what I'm talking about.

ARN

The motor came in the bike never got a card.It was built 5 yrs ago,or approx 5000 miles.Somewhere in the 250/260 @.050 Part of the reason why I'm building another motor so I will know what everything is inside the block and I want all aluminum. Polished!!

[mdross1]

The block will be an aluminum Donovan standard deck,raised .390 big block cam ,.904 lifter bores,1/2" wider pan rail 4.125 bore.Want to run the longest stroke the block will swing,without overtaxing anything.aka rod ratio,comp height.If someone convinces me that I can use an SB2 topend with little to no hassle,thats what will go on this motor.

[Joel Dubose]

The block will be an aluminum Donovan standard deck,raised .390 big block cam ,.904 lifter bores,1/2" wider pan rail 4.125 bore.Want to run the longest stroke the block will swing,without overtaxing anything.aka rod ratio,comp height.If someone convinces me that I can use an SB2 topend with little to no hassle,thats what will go on this motor.

An SB2 can be bought used very inexpensive , and parts are available. Most of them are used from the NASCAR arena. Having said that it would require a header change as well as other components. There a bit heavy and also big in size. That's why I suggested the 15* heads. I could recommend a set that flow big numbers and would work great for what your doing. It's much lighter and more compact. I have two versions that are going to become available in the near future. Most of the hardware like valve covers and intake manifold are a direct bolt on. The fact that your going to use a big lifter bore will help you also to use an offset lifter for the use of big dia pushrods. The heads that I'm talking about flow better than 400 cfm. There are other heads that are big flowing ,smaller lighter packages as well on the market. Some of them out perform the SB2 heads. If you would like to talk about it PM me and ill give you my number .