Want more power from 5.9L LA TBI!

IMHO the 308s also like a single pattern cam. The exhaust is so good that using a dual pattern cam lets too much intake mixture out and hurts power.

The real answer is to find a company that specializes in these engines.

R.

The 98-92 360 TBI engine is much less tolerant of changes, it can not compensate as much as the MPI magnum engines. You may get some more airflow with a fresh air intake and headers/dual exhaust but it will not add more fuel to compensate and eventually you will start to get lean misses and surges... with any significant change. If you are gonna do any thing mabey throw some magnum ex manifolds on then a dual exhaust and cold air intake and a set of 1.6 roller rockers, that is about all the computer can hangle for changes. If you pull the heads it could probably stand a set of thin head gaskets or a little milling but thats it. Even all those changes are gonna net you very little cept mabey another MPG or two because they will lean out the mix. You may be able to step up the fuel preasure if you add a 93 style fuel pump and a regulator but you can't get crazy with that because more than just a couple pounds over stock and the injector will not work right. There is no one re-programming those computers any more (if ever)either. All told I bet you can't get more than 20 HP without stuff not working properly anymore.

If you are willing to do a carb you could make quite a bit more power very easily. Put on a t-quad on a stock intake, some headers, 1.6 rockers 340 valve springs, dual exhaust and you could easily get 50 more HP, a cam change, performer RPM intake and head milling along with the other mods and you could easily get 100 hp over stock.

I've heard of guys switching over to the GM TBI set up...no shortage of aftermarket for that stuff, but if you go to that point you may as well find a 92 and later van and throw a Magnum engine and harness in it, but it's kind of against why you are buying the van as it only has 40,000 miles. I had a 90 Ram with a 318. I put a set of dual exhaust and it had no ill effects. I say put some headers, dual exhaust, maybe even a 4 bbl intake with an adapter for the TB and see what happens.

My dad's old '91 360 TBI van was a rocket compared to the '98 360 magnum van he had later. I know on paper the TBI 360 made less hp, but it was way quicker. Both had 4.10's too.

best bet is to put the electronic ignition Kit on it so u will be able to put a carb on it, then all the basic power adders, cam, double roller timing chain, ported heads with bigger valves, headers, exhaust, 1.6 rockers, electric fans, maybe 3.55 gear (or if it has that already then upgrade to 3.90 gears) then that will wake the truck up, but as far as the factory TBI goes just open element air cleaner, with duel exhaust and the lower gear in the rear is all u can do for it.

my 89 318 TBI is pretty good. It's got steep gears (390s?) and the 3 speed TF.
The motor and computer is pretty well set. You have to tune for best performance with what you have. Make sure the injectors are nice and clean, along with the intake and valves. Try Techron and/or Seafoam. Change the oils out for synthetics, and pump up the tires.
One thing that could help and would probably not be seen by the computer would be a steeper gear and a 518 trans with add-on switches. Adding a 4th gear and maybe a lockup should get you more off the line power and better freeway manners and MPG. Should fit, they came in later vans.

As mentioned headers, good tune up, fresh air might help. If you don't care about the TBI you could go w/ a dual plane intake and small 4bbl as well. Probably pick up a few there.

A good dual plane with a 600 edelbrock carb really woke up my 318 TBI truck, I put headers and duals on it too but the intake/carb made the biggest seat of the pants improvement.

Thanks all, some great "rare sense" ideas.