350hp 406 sbc
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350hp 406 sbc A guy has a 406 sbc that has been rebuilt with a stock cam. My question is what would it take for that engine to make 350-400hp with a set of vortec heads. What size cam would you guys think i should use. Any replies would be greatly appreciated. Thanks
400 hp will be a walk in the park with a set of vortecs.i'd say get the comp cam xer hydraulic with .477/.480 lift with a performer air gap intake and a good 650-750 carb and it will make well over 400 on it's worst day.
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I have another question that i forgot to mention earlier. He said the pistons are speed pro .100. I asked him what would the compression be with a set of vortecs and he said with 64cc heads 11 to 1 and 68cc heads 10 to 1. Does any of this sound correct to you guys?
with a flat top piston a 406 will usually have compression between 11:0-11:6 with a 64 cc head.if they are .100 dished i'd say around 10:00 or so and 12:5 to 13:0 domed.hopefully they are not domes because that compression is too much for a steel-headed pump gas motor,spark knock would be terrible and your motor would probably not last long at all.
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I was thinking the same about the compression being 12:1 or 13:1 also. Instead of vortecs i would have to use a set of 76cc heads. Will i still be able to acheive my goal with 76cc heads and the 274h cam?
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274h on a 406 won't be bad at all.. I ran a 274h on a 355 for a while, then went to a 284h.. 284h idled like ****, 274h was very streetable.. 274h on a 406 should be cake. 268h is too small, and will have like a 5600-5800 redline probably in a 406, if that.. not to mention very tame sound. 274h at least.
Peace,
Josh
Peace,
Josh
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Making power out of a 406 is a cakewalk. As for the cam..if you really wanna make some power go ahead and buy the retrofit roller kit. I run a 406 (see sig) that put down 514hp/564tq at the wheels. If you want to stay with a flat tappet ive had good luck with the Comp Magnum series 280 (280/280 .480/.480) and a 2500 stall. If you want some more details about a buildup i can help...just shoot me a messege.
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Ok, i decided not to get the vortec heads but get a set of AFR 195. The pistons are .100 dome and the midwest motorsports catalog says the compression will be 10.7 with 76cc heads. My question now is will the compression be too high for pump gas because the AFR's are 74 cc heads, therefore; raising the compression a little higher.
with a decent sized cam you will be ok. you may to have to mess with your weights if you are going to use an hei distributor but your compression should be o.k.what are you putting this motor in?
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So now I've decided on the following for certain: 274h cam kit, performer rpm intake, 670 holley street avenger, afr 195s. I'm gonna have thes pistons changed so I'll have 10.1-3. compression. Any more suggestions? I plan using a 700r4 trans. too. What gear ratio I should run with this tranny to take advantage of this cam with this being a daily driver?
Last edited by Pr0blumz; Feb 27, 2006 at 11:30 PM.
If the car is heavy I'd try to stay around 3.73's if at all possible. However, your stall is gonna matter more than the gears.. but that cam is going to be very streetable on a 406.. that's for sure.. In a 350 I shifted at 6200 and had the idle up on a 6 speed around 850, and it was great. It made 338rwhp on shorty headers with a messed up holley carb.. a/f was completely screwed.. I ran afr 190's with mild porting.. flowed like 260cfm.. I think the combo your talking about is good for an honest 425-450 flywheel horsepower at a very low peak due to cubes.. and I think you'll be very happy with the setup.
Peace,
Josh
Peace,
Josh