I've almost got the 408 with the eagle 4" kit in my possession. Can't wait to get it finished.. anyways I'd love to know if it's possible to have a direct port injection with a 408. What would need to be done? I'm not going with a carb since I found Hughes and Edelbrock have a MPFI intake kit with the fuel rails that looks almost identical to the airgap. I'll grab some better injectors for that. But ya back to it, is there a way to have a DPI on this engine or would it be pointless if I got stage 2/3 injectors

 

The stock manifold is port injection, as is the hughes air gap. (which is made by edelbrock.....) You will need a custom tune on the PCM to run the engine right though.

 

I know the stock is multi port.. and that Edelbrock makes the air gap. When I looked at the air gaps on Hughes site tho, it looked like most of them were made to switch to a carb. My main question was, is it possible to get direct injection like a deisel on this engine?

 

No. That would require re-engineering the heads.

The air gaps on hughes site come with an adapter for the stock dodge (holley) throttle body. There is also the Mopar M1 intake, it came in both two, and four-barrel flavors, but, has been out of production for a while now..... gotta be lucky to find one.

 

Ok thank you. Personally, would you settle for an air gap or wait til you could find an M1 intake?

 

Prices are about the same.... the air gap requires you to modify the fuel cross-over line, the M1 does not. Power band is about the same too. If you can find a 2bbl M1, that would be the hot ticket.... but, finding one is going to be a stroke of pure luck. (if you do find one, buy a lottery ticket too.....) If you have the time to wait, and try and find one, go for the M1. If you don't, grab the air gap. The stock intake will choke the 408.

 

Ya I plan on everything from the block up being aftermarket. Long tube or shorty headers? Gotta have 3" exhaust ran too. I know I'm getting a little off topic but you seem to know what youre talking about man. I have most parts picked out already but I'd like an experts opinion on a perfect 408 build. I'd like above 600 horses and 550 torque but I'd settle for 550 horses and 550 torque I want H beam rods with forged aluminum Pistons, ***** thumpr cam hydraulic roller lifters 522 509 duration is 291 a 311 lobe separation is 107, Edelbrock aluminum heads(unsure of which would be best), roller rocker arms(unsure which brand or type if it matters), the m1 intake(now that you've mentioned it), those sexy Mopar valve covers, mega viper rebuilt tranny, may upgrade to 4.10 rear end(already have 3.92 9.25 rear end right now). Am I missing much?

 

Ouch. That's gonna be fun to tune..... It probably won't idle below 1000 rpm, you will have very little bottom end power..... basically, it won't be usable as a truck. (be able to smoke the tires forever though.....) Figure a pretty high stall torque converter in there too....

Go with long tubes, and the biggest valve heads you can find. Think I would also look for the M1 four barrel..... it is more matched to what you have in mind. Harland Sharp roller rockers, (stock ratio....) or even have the heads milled/drilled for chevy style rockers. (adjustable.) I would seriously consider rocker stud girdles, and tall valve covers as well.

Or maybe.... go with forced induction, and build the motor with that in mind. Easier to get to the power numbers you are looking for, and MUCH more streetable. (not to mention, still useful as a truck......) You would still be able to smoke the tires forever.

 

Are you basing what you said in the first and second paragraph on the cam profile? Theres so many different variations of cams idk what I should go with tbh... Id consider a supercharger, no turbo tho.. I'd like to stay away from a supercharger altogether tho. I will sacrifice horses if it means not having one on

 

A local guy near me has a 600+ how 360 (bored to a 408) he idles at about 700-800 rpms and has the old school shakey idle (which I like tbh) and has a lot of low end torque he can chirp the 35s in every gear. I am planning to do what you want to do (but at least 700hp and 800 torque when find allow but I already got a list together) and then swap a Hemi into the truck with even more power. In a truck you want to make Max torque at 3,500 rpm or below.