Have a '91 150 w/302 Fuel injection. Like the way it runs ( better than my cop car, '01 Crown Vic ), just looking for a way to get a little more out of it quick & cheap. Am thinking headers, maybe one of you old timers could offer me some advice. Guy I bought it from claimed it had a new Jasper long block about 40,000 miles ago. No paperwork, " lost it in the divorce ". Haven't crawled under it yet to look, supposed to be a sticker on it near the oil pan if in fact it is a Jasper.Haven't drove it much yet, was told the bottom rad. hose was rubbing trans. line when inspected. Just put it in shop this morning at Tech. school. Am having flush & fill, new thermostat, all new hoses, tune up, & a bunch of small stuff done. Also tranny flush & new filter. Is a 2wd reg. cab long smooth side bed. Bought it for a work truck, am thinking I may drive it when it gets done & park the old cop car. Other idea for power upgrade is where I'm lost. Know nothing about fuel injection, am figuring whatever is on it from the factory is equal to a 2Bbl. carb. What would I want to do to make it equal to a 4Bbl.? Back in the old days, would have bought an Edelbrock & Holley. What do you do with fuel injection? Can contact me at mae_hyun@yahoo.com. Near St. Louis, Mo. are there any decent places here to get performance parts? Don't think " The Zone " is really the place to go. They're okay for normal replacement parts, don't think they would be that good for performance stuff. Don't want to get internal yet ( cam, pistons, valves, etc. ) IF it's really only got 40,000 on it. Would rather wait till it gets up around 75 -100 & do a complete rebuild then.

 

Sorry there are no easy bolt-ons for power. The 2 initial bottlenecks on this motor are the cam and exhaust system, swap both and the motor will produce up to around 275hp with no other changes. But you can't throw just any cam in it.. it has to be EFI friendly and the short list includes the Comp 31-255-5, add headers and a decent single or dual exhaust and you're all set.

Other than that these trucks need gearing, check the drivers door pillar for an axle code, that will decode to a gear ratio. Anything less than 3.55 with stock sized tires delivers less than sporty performance with the 302 and 3.73 to 4.10's are better.

 

Conaski, thanks for the reply / info. What would headers do without anything else? Not wanting to go internal right now & don't even know what kind of mileage I'm getting, rather not change gears yet. If I do, how do I get the speedometer to read right? Is there still a gear on the end of a cable plugged into the tranny or have they changed them by now? If still that setup, how would I know what speedometer gear I needed (part# / description { color / number of teeth / etc.})?

 

I might add, Simply go with the mind set, "let it breath" an engine is much like an air pump... Dont go with short headers... If you take the time to swap the cam, make sure you match everything... Throwing HP parts at an engine wil not make it go faster or produce more power unless it is in tune. Tune meaning, a small lift cam is good, so a big lift would be better, is the wrong philosophy.

A nice mild RV cam, Producing low end power, 3:73 gears, complimenting low end Torque (assuming you have 15 inch tires) a free flowing exhaust. ( long tube headers) and a good induction system. Try to remove that nuckle in the exhaust port to... A hotter ignition would also be wise.

HP aint cheap, but not building an engine, with all the parts, not complimenting each other is really really expensive, and will produce bad results.

1 last thing... You might try to contact Jasper. They have build specs on file for there engines, You may already have a adiquate cam, and that might save a little money.

 

Mustang6147, what you say makes sense, next concern is the smog laws ( see other question ). Know it's exempt from inspection due to its age, concerned about it being legal though. Was looking at Hookers on the computer, thought if I got the " shortys ", I'd be legal, now it says NOT street legal. Preferred the long tubes anyway, just trying to stay legal. Any advice on that one?

 

I dont know your laws, I have enough issue's with HP , and my laws LOL.

I had a Mustang with a 302, with an edlebrock instake 850 dble pumper, headers, port and polish intake and heads, Mallory hyfire ignition. It had no converters or pump, although it wouldnt pass the emissions visual inspection, it did pass the exhaust sniffer test.... SO I had to put cats on it, for the test. Its all a scam, but thats another topic. I had a 460 in a capri also, same issue's...

My opinion is, you may have a better cam then the engine came with stock...

 

Longtubes and a small single exhaust(2.5") will produce much better TQ from idle up, shorties are mostly wasted without a cam and gear change because they don't really do much below 3000rpm on a 5.0 and the whole powerband is below 4000rpm with the stock truck cam.

Is your odometer mechanical or electronic? If it's electronic it gets a signal from the VSS on the rear diff so gear changes don't affect it. If its mechanical then the speedo is cable driven off the tranny and you will need a new driven gear, there are several sites that have the color codes and tooth count for these gears, a web search will turn up what you need.

 

Yeah tell me about it. I took our little ranger in for it's semi anual sniffer test a couple weeks ago and figured I'd try a shop a little closer to my place instead of the one I regularly go to. They didn't test it because apparently it had an exhaust leak, and what really burned me was they didn't call to say that.. I only found out about it hours later when I went back to gets it. When I asked the guy behind the counter that the deal was he said "yeah.. we won't test anything with an exhaust leak or even a fluid leak". I laughed and said.. what in hell does a fluid leak have to do with tailpipe emissions? He said.. "Oh that's the code.. we're just going by what the regulations say." Friggen *******. I took the truck to my regular guy and surprise... it passed easily.

 

That is what happens when people get a little power, or feel like they are in charge...

I adjusted my original post, and will reiterate, Sugesting attempting to cantact jasper, to find out what cam was used in there builds...

It would be really nice, if he didnt have to open up a good running engine, for minimal gains.

 

X3 on the long tubes & exhaust , gears dependes on tire size (how tall ). You can check your laws but i don't think long tube headers will stop you from passing emissions ??? Some easy things to do is set your base timing from 10 to 12-14 degs . If you don't want to get into the motor to do a cam , you could go to 1.7 roller rockers , that will give some more cam lift.... Lew

 

Just wanted to say THANKS to everybody for their advice, Am not sure what will happen if I go with long headers & true duals ( not this Y-pipe AFTER the crapalytic converter like they do now ). Due to all the advice I've received, IF I do anything, it'll probably be that. Does not have to go through the smog test due to its age, only safety. Just worried IF I get checked for some reason & they find that. Will try to ask someone at a shop here when I get a chance. see what they say. Remember when I first moved here from New Mexico ( NO inspection of any type there then, don't know about now ) the shop I took my car to ( '77 Monaco 4dr. 318 2Bbl. ) didn't have a pump ( smog ) on it & they were going to fail it. The guy called the Highway Patrol & they told him " If it's an out of state car & there's no sign it ever had it, ( brackets, blocked holes in manifold or exhaust ), it was okay. So I got by with that one. Would love to go with long tubes & dual Thrush or Cherry Bombs. Would sound great. Any thoughts on these K&N (?) air filters I see advertised all the time? Never thought just changing the air filter would do that much. Installing a ram air set-up / shaker scoop like the ORIGINAL Mustangs ( Boss 302 & 429 ) had, yes, I can see it. Just changing from a stock air filter? Seems doubtful to me. Still don't know for sure IF it really has a Jasper or not. Will try to have the instructor at Tech school check it for me since they have the truck & will for a while.

 

K & N filters are good. I have used them with out any issue's. I wouldnt hessitate to recomend them either. However there was an issue a few years back, People not knowing how much oil to use, and more is better mentality, there will be a few guys that swear oil and mas sensors are bad. I have a post on here about K & N in Air/ intake section, and have done it on many forums. The over oiling thing was a problem, but it was owner error. SO K & N gets my thumbs up...

 

Mustang6147, Thanks ( again ) for the help. Kinda know where you're coming from on the over-oiling filters. Work on lawn mowers on the side & have to explain to people A THIN FILM, JUST ENOUGH TO STOP THE DIRT, not soaked in oil

 

If you were going to do one or the other ( headers / exhaust OR K&N A/F ), which would you recommend first? Expect the filter would be cheaper, think Hookers were going for around $150/pair when I looked this morning. Plus exhaust system all the way back, probably about a 3 or 4 stage process ( headers, not installed, exhaust for one side , not installed, exhaust other side, then finally get it all installed. Just went back & re-read all the replies, notice you mention changing the ignition. Would that do anything with out doing the other stuff first ( exhaust - A/F )? What would you suggest? Remember in the " good old days, an Accel " Super Coil " was the way to go. Does that still hold true for the new electronic ignition systems? My memories are from points & condenser days.

 

I think the suggestion was to advance the timing, the base setting is 10 deg BTDC and these motors will often tolerate 2-4 deg more advance depending upon the grade of fuel being used. Just be aware you have to remove a plug to disable computer advance before setting the base timing, it's called a spout plug and it's in the TFI harness. More timing will increase TQ and that will be noticable without doing anything else. Air filters are a complete waste on a stock motor IMO, and when it comes to the 302 that stands until you have the complete top of the motor replaced with better parts, the little wheezor just doesn't move enough air in stock form to really benefit from a better filter. You get to try it out for yourself however if you like.. it's your money.

If you want to do something else that won't cost any money, assuming the truck sill has the stock exhaust drop everything behind the cats and leave it off.. no it won't be too loud. If the cats are intact you could hollow them but then you'll definitely need a muffler to keep the smokies at bay.