I have put thought into all kinds of engines for my 88 Dakota over the last 2 years and I just need some closure weighing in on factors here. I was pretty sure I wanted to build a 408 stroker engine from a 5.9L Magnum block, run a cam and keep the multi-port using MegaSquirt. Remember my truck is extremely light, and I am after the old school muscle theme.

Then my buddie was saying strokers are not really a high RPM engine and for the money there are much better ways of achieving same output. Since its not really a good idea to boost a stroker I am now leaning on building a boosted Magnum V8...if I did this it would be a twin top manifold mounted turbo setup this way I can run a much less restrictive exhaust and have it muffled a bit from the twin turbos not to mention not robbing engine power to create the boost.

Now its a bit of a fight between boosted 318 or 360...I am being told the 360 could be about 40lbs heavier. I do like the novelty of having the 360 in a truck that only offered a 318 and that wasent until years later but I am not sure if there is any good reasons to go with a boosted 5.2 over a 5.9?

This was the engine bay when I first got it:



Then I removed the emissions right down to the vac solenoids and this is about as good as its going to get for me with this pos TBI 238ci, only other thing I will do is move the computer from the fender to the passenger firewall and move the battery to under the bed where the gas tank is...and the gas tank to where the spare tire was...



This was a Dakota that already had a Magnum engine that they cleaned up exactly how I am doing my engine bay minus the tubs, I already have tons of room around my LA engine and with the Magnum the accessory rack becomes tighter and centered creating even more room. However with my 87-90 front end the core support leaves no room after a full size radiator, AC rad and electric fan with a small block V8 behind it. I photoshopped in twin manifold top-mounted turbos where the dual cold air intake tubes were, they will fit perfectly and cleanly here under my hood being symmetrical...but it only leaves one challenge; the intercooler for the turbos.



I have absolutely no room on either side of my core support for an intercooler but I don't think that is a problem if I were to split it up and run two smaller intercoolers one on each side horizontally against my hood. I don't want a scoop or cowl induction but I have always wanted to do dual louver pods, they will grab air and force it through two small intercoolers and then down into the engine compartment from there (or in reverse at high speeds) I know without a low enough chin spoiler the air goes up through your engine bay and creates drag against the bottom side of the hood. When all said and done after the tubes curl from the turbos toward the firewall up against the hood > across the intercoolers > toward the front they can come back down with a cone air filter on each side basically where they are in the photo above behind the headlights where the most (pos/neg?) pressure is for intake system filters to be located. If I did the custom plumbing and had the manifolds made would this system work much better than a NA 408 Magnum stroker?? Can I potentially run this twin turbo setup down the line on a stroker if I built one now?

 

I think the extra .7L would end up overpowering that extra 40 lbs.

 

Not much experience here with mopar, mine is mostly GM. But I believe the basics are the same. That being said, what RPM do you plan to turn this motor? A stroker that is well built and balanced will turn 7,000 + rpms easy. If this is going to be a street truck, I would build the 408 high compression, all forged bottom end. And then latter you could spray it 150hp if you wanted. Even without spray, the motor should be able to make 4-450rwhp and that is going to be hard to hook up even with drag radials on the street.
Unless you have a lot of money and time to spend building, testing, designing, a twin turbo system, usually they end up being a big disappoint, and never completed.
But at any rate, from the beginning you need to decide what you are going to build, because if its a blower you need to keep the compression down, and if its NA you want a higher compression.
Good luck!!

 

Thanks for the input. Some are telling me that the 318 revs up faster than a 360 and I am not sure if that has anything to do with the fact 318 is internally balanced and the engineers had to kind of 'hack it up' to make the 360 out of the original casting which resulted in it having to be balanced externally. If this is the case then they make 318-to-360 & 318-to-390 stroker kits which will utilize the original internally balanced 318 design.

I need to do more research about the differences then just balancing but I agree the .7L should overpower its additional weight however design flaws could be another factor.

 

If you're boosting, there's no specific reason to go with a 5.9. Heck, you could go with a 3.9 and still have a pretty quick truck.

The main problem with boost, as I see it, is that it's one of the quicker ways to empty your pockets of ALL YOUR MONEY.

You know, the third alternative would be to go really old school muscle truck. Built a stroker, you can use an LA if parts are easier to get. Crazy f-ing cam, ported heads, old school electronic ignition--like an old MSD, and a tri-power or dual quad carb setup. Would get really lousy mileage, but you probably don't care about that, right. Use an old school 4 speed, heavy clutch, and a 411 rear end.

T'would be a bitchin truck!

 

Yeah I being told that about the $ in testing and tuning turbos.

I would rather run a block on Multiport with Megasquirt and use Magnum parts for even greater performance. I was looking at an 8.75 or 9.25 rear end with an auto transmission using a manual valve body.