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sdavid · 05-02-2009, 09:53 PM

Airgap is a good intake. The performer will do fine for what you are building also. It should not take much to make the 30 over 400 a strong engine. The vortec heads will flow good, but they will limit your cam lift height unless you get them machined. Sounds like your plans are for a cam that is not too radical so you should be OK. Use a cam that will have a RPM range of 1000 to 5500 and it will probably be what you want. Something like a 268 advertised duration, or maybe a tad larger with the bigger cubic inches. And all of this depends on the compression ratio you are going to have.

Most cams are advertised for 350 cubic inch motor, so the same cam in a 406ci motor will act smaller.

You might want a 650cfm carb to help the new motor breath.

05-02-2009, 09:53 PM	#2
sdavid Registered User Join Date: Mar 2005 Location: Livingston, TX Posts: 56	Re: Rebuilding my sb400... Any suggestions? Airgap is a good intake. The performer will do fine for what you are building also. It should not take much to make the 30 over 400 a strong engine. The vortec heads will flow good, but they will limit your cam lift height unless you get them machined. Sounds like your plans are for a cam that is not too radical so you should be OK. Use a cam that will have a RPM range of 1000 to 5500 and it will probably be what you want. Something like a 268 advertised duration, or maybe a tad larger with the bigger cubic inches. And all of this depends on the compression ratio you are going to have. Most cams are advertised for 350 cubic inch motor, so the same cam in a 406ci motor will act smaller. You might want a 650cfm carb to help the new motor breath. __________________ '81 C10 Stepside, SBC, T350, Wood Bed, and silverado options '87 K5 402 BBC, T350, 3.73s locked up, 2.5"Lift, 33x12.50x15s Last edited by sdavid; 05-02-2009 at 09:57 PM.