408 or 351 with Vic Jrs ?

2002BLGT

Well-Known Member
Dec 18, 2003
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Bedford VA
friend of mine is debating on building a 408 or a 351 and using a set of Vic Jrs , the cam he has picked out is a hydraulic flat tappet with duration of 284 int /292 exh 241/249 at .050 and lift of .560 int / .582 exh

he wants to keep compression in the 10-11 range with a forged flat top piston


so the question is , to stroke or not to stroke , gonna be using either a vic jr or performer RPM intake as well , what would you guys suggest ??
 
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Go with more cubes. The Vic Jr's probably wouldn't be the optimum head for a 408, they would be better suited for a 351, but they also should be a head that has plenty of material for porting. If you already have the heads, use em and maybe someday have them professionally ported. If not I would save up for some CNC Twisted Wedges or some AFR 205/225's.
 
I like the vic jr's i have on my 351w. I have always wanted to build a 408 stroker. The vic jr is a great head. Yes the AFR 205 would be a better head but the vic jr's can flow just as much with a little work. They will be able to support the power you will see with either combo.
 
A flat top piston will give you too much compression with a stroker motor. More cubes = more compression. Usually a flat top piston with a 393/408 with adequate valve reliefs and zero deck will give you 11+:1 compression, a dished piston will bring it down to a more pump gas friendly 9 or 10:1.
 
A flat top piston will give you too much compression with a stroker motor. More cubes = more compression. Usually a flat top piston with a 393/408 with adequate valve reliefs and zero deck will give you 11+:1 compression, a dished piston will bring it down to a more pump gas friendly 9 or 10:1.

Exactly. Most combustion chamber sizes will require a dished piston for your desired compression ratio. There is nothing wrong with a dished piston, I was just pointing out that you probably wouldn't be using flat tops.
 
How much compression are you going to run? Aren't TW's like 60cc chambers?

Not sure yet Jared.
I pick up the block and heads tomorrow morn.
The heads have been shaved twice since the last time they were cc'd (they were 72cc). Once for a leak/warp, and a second time to fix the Sh@# job that was done the first time.
I think it should be between 10.5 and 11.

If I have to swap the heads, I won't be too upset. The TW's are a little small anyway

jason
 
the cam is a mild cam should make good torque under the curve , the idea is not not have to spin it to 7500 to make power and that cam I picked out should work good with a 351 or a 408 especially given the nature of these heads not being quite as good as the afr 205s