393 vs. 408

bgjohnson

Founding Member
Sep 1, 2002
963
0
16
johnston,iowa
okay guys here's the thing i am dealing with. i recently bought a 351 with a complete bottom end(probe pistons,eagle I beam rods, and a stock ground crankshaft) the only problem is, they said the crank needed polishing because of "flashing" and i thought okay not bad at all. well i got to looking at the crank and holy motherF***er, it's not just flashed, it's really started to rust. and he had a offset ground in the crank so he has the right bearings and everything for it so i would have to get it reground and buy new bearings for it. here's the other issue, the probe pistons i have are for boost which would bring the compression to about 8:1-8.5:1 which i DO NOT WANT. i would up for boosting it later but the crank is a stock cast crank which i don't readily trust for about 500-600hp. so what i'm thinking is that i sell all the bottom end and buy a 393 or 408 stroker kit for it from CHP. now the 393 kit i want is about 1600 bucks, the 408 is abou 1750. which of these two would be the best streetable engine combo, i've heard good things about longevity for the 408 and that is has good low end grunt. i guess the 393 is a higher revving engine in order to get the power. so after reading all the BS i just typed, what do you think i should go with or any experiances from the two would be greatly appreciated. :nice:
 
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tjm73 said:
The difference in rod angle will mean nothing. It will cost the exact same ammount of money to buy/build a 393 stroker as a 408. I'd just get the 408 and be done with it.

nothing? not quite...

it won't mean much, but rod angularity does make a difference in piston side loading, but how much longevity are you planning to get out of this motor, and for what purpose? if you're planning on spinning this thing at like 7,000+ rpms, don't expect it to last long, but if you keep the usage reasonable, it'll last just like any other windsor based motor
 
thanks for the reply guys. i'm just wondering if i should notice a difference in longevity. i may be putting boost to it eventually. so in these two setups will it really make a difference will the rod angle? and one more quick question.

since the block is already machined, all i need to do now is have them notch the cylinder walls right?
 
Damn will every body stop bitching about rod angle,Im tired of hearing this crap.

As a matter for fact,a short rod tends to make more power than a long rod.And long rod motor tend to make more low end torque,why,cause the longer piston dwell time at low rpm,but this kills them in the higher prm range.

So,basicly,screw rod angles.Get the bigger motor,it will make more power.
 
yes, to clear the rods. i've asked around peoples reply is, umm i think so. so i don't know for sure. but i'm just gonna take the block to the machine shop when i buy the stroker kit and have them order the bearings and rings.
 
bluevenom867 said:
Damn will every body stop bitching about rod angle,Im tired of hearing this crap.

As a matter for fact,a short rod tends to make more power than a long rod.And long rod motor tend to make more low end torque,why,cause the longer piston dwell time at low rpm,but this kills them in the higher prm range.

So,basicly,screw rod angles.Get the bigger motor,it will make more power.


no need to be so rude...he just wants all the info he can get...I'd probably go with the 393, but that's so i could save a little dough on the pistons (same as 302 c/h based on rod lenght) and that's purely my preference...

don't be an ass...
 
txstang84 said:
no need to be so rude...he just wants all the info he can get...I'd probably go with the 393, but that's so i could save a little dough on the pistons (same as 302 c/h based on rod lenght) and that's purely my preference...

don't be an ass...

Sorry if I offended you,bud.

Its just this has been something that has been brought up on almost ever stroker thread.And mostly there non signiffcant details like this.And for one,there mostly from bias people-like yourslef.Your building a 393 with 302 pistons to save money.And thats cool :nice: .

Simple fact is,with the same parts-the 408 will make more power.Period.

P.s.-reliablity is not an issue with either motor.
 
ok thanks guys. and Venom i saw the couple vids of your car and wow it seems really planned out and a good setup, very nicely done.

and i still have the question if i have to notch the cylinder walls at all?


and one more question that's really been buggin me. the guy that had the block machined had oil restrictors put in the block, now should i worry about these using the car on the street and drill them out? or just not worry about them?