First of all my power goals are 500-550rwhp on motor and two kits on top of that 150 plate and 200-250 fogger. I had myself talked into going turbo but for some reason I just cant wrap my head around it so nitrous it is. Truck will be a daily driver type deal although I doubt it will get driven daily. Anyway thinking of doing a 408 or 390 from AES pros and cons on both im looking to have some sort of longevity so would the shorter stroke of the 390 be better?

 

Myself, I really like what I have been seeing on the 390's. I like the idea of the shorter stroke also.

 

I'm making 455 on my 370 with dome pistons (11.9:1) and l92 heads.. Im running a NOS crossbar plate with .060 jets.. But I do like the 390 alot better than 408..

 

What is the stoke on the 390? Havent seen too many guys running that ci yet. I would think the power difference NA would be neglegable from 390 to 408 so I would go with the shorter stroke for better reliability (although I have no info to back up the 390 being more reliable just seems like it would be).

 

3.8ish i think. Somewhere between 3.622 and 4. The theory is good but there is just not a ton of then out there to see if they are actually more durable.

 

Either will work just fine at the HP level you are looking at. You should have no crank problems unless you create them in a bad tune or loss of oil. We have some great motors as well if you are looking for other options. We have 800HP rated 370Ci builds starting at $2959 and 408Ci builds starting at $3849. Let us know if we can help.
Thompson Motorsports
972-853-0518

 

Like Atomic said, there aren't a ton of 390's out there. You should do something different and go with the 390ci. Not saying I wouldn't rebuild my 408 again but I would be interested to see how the 390 likes nitrous and the combo of parts you end up using.

 

The 390 appeals to me too and like said above I don't think the power diff between a 390 and 408 will be that big of a difference. So I won't be losing much on hp the shorter stroke the 390 just sounds better to me and the piston skirt shouldn't come as far out of the cylinder as it would with a 4'' stroke.

 

Is the rotating assembly in production or is it custom made for aes? Pricing comparable to a 408?

 

The 3.8 stroke is exclusive to AES as far as I know but I believe they will sell you a rotating assembly. As for pricing pretty much everything I have seen is pretty comparable.