I have a nice looking '88 conversion van stock 302 and 3.55 rear.

Would like to be able to tow something but the van can hardly get out of its own way empty.

What can I do to get some towing power?

Was thinking a gear swap and if that didn't work put in a 351. Could also fool around with tuning or chips I suppose. Thoughts?

 

Make sure the 5 liter is in good working order and properly tuned. And that the cat's are not stopped up. I tow with my '95 5 liter and it does a great job. Your '88 is a lower HP/TQ 5 liter but its not a big difference. The Conversion van may also be heavier and that doesn't help either.

A free flow exhaust and a low restriction intake with K&N filter will help.

 

Just tuned up the van. Everything good there. Have the K&N already. Tried some different exhaust. No noticeable gains from anything I've done.

I know a gear change to 4:10 would help. Just wonder how much?

 

A lower gear will always help pull a load easier but I would hesitate to upgrade to a 4.10. I have a 3.55 in my van and it turns quite a bit of rpm at cruise on the highway. I had considered a 3.73 but decided against it. Glad I didn't now.

I still think either you are heavy or the van is down on power somehow. Does it still have the stock catalytic converters? Have you weighed it?

My van weighs 5300 lbs empty and I tow about 4000 lbs along with more than 800 lbs of cargo. The van tows fine with this load. It will cruise all day at 80+ mph and climb most anything east of the Rockies without too much trouble.

Steve
'95 Clubwagon XLT

 

I would like to be able to tow 4K! Have a 6X10 cargo trailer and I have to really push the van to tow it. Probably 2-2.5K total. Can't even look at a hill without slowing down.

I installed a tach to see how things were doing. I'm only doing about 1500 -1700 RPM at 65mph. It rarely goes over 2K running around town and that is when I put my foot in it. I even checked the tag on the axle to make sure it had 3.55. Says it does. Maybe I'll have to jack it up and do a rotation count. Don't do any highway driving so 4.10 isn't an issue for me.

How are you turning high RPM with the same gear set?(3.55). This is my second van with the same gear and both had no power and ran low RPM.

 

A 3.55 gear with the OE (for my van 235/75-15) tires should turn 1900 pm at 65 mph, almost 2200 at 75 mph and 2450 at 85 mph. A steady 80 mph, my usual tow speed, it turns 2320 rpm. That's a little more than a "relaxed" cruise rpm. I like it because at that rpm I am on the engine's torque plateau so only the steepest climbs require a downshift. If I had gone with the 3.73 I would be turning almost 2450 at 80 mph.

A 4.10 gear would turn 2175 rpm @ 65 mph and over 2500 rpm at 75. I would suspect that you have a 3.31 gear. That's a common gear for E150s (that's what mine had when I bought it). If so; 65 mph should turn 1757 rpm. If your tach is accurate and you are less than 1700 rpm then you are down around 3.00:1 and that is your problem. A 5 liter wouldn't pull your hat off your head at 1700 rpm.

Oh, and this time last year I moved 600 miles and towed a U-haul 6x12 (their standard double axle enclosed trailer) that distance. I made two trips hauling my shop equipment. I had both the van and trailer heavily loaded. Probably 1000 lbs in the van and the loaded trailer at over 5000 lbs. I could really feel the load on the one long/steep climb but it only required 3rd gear and pulled 70 mph with half throttle.

Steve
'95 Clubwagon XLT

 

You drive a lot faster than I do. Very rarely go on the highway because we live in a rural area.

Sound like a gear change is a good place to start. If I could get the kind of performance you have I'd be happy.

 

I tow very long distances regularly (500-1000 miles) and you have to be able to make time and keep up with traffic. You should have no trouble with that little trailer if the van is geared correctly. Since you don't use interstates much you might be able to get away with the 3.73.

Here is my rig:

 

Nice setup. I couldn't even tow the trailer right now.

I'm going to go with 4.10 and be done with it. Should be good for the type of driving I do here.

 

Trying to fix this problem with gears is a bandaid for a larger problem. I too have a 302 and it can tow a 4000 pound load just dandy. It has 3.55s and an AOD no less. If it can't even get out of it's own way, then you have a problem and gears are not your solution. I would suspect either engine condition or some kind tuning issue (<- and I don't mean just plugs, cap and rotor) to be the real problem.

 

Engine condition is good. Did a leak down test and everything.

I know the gearing isn't right because we aren't getting a lot of rpm out of the motor. These 302's don't make any power at 1500RPM. I'm always taking it out of OD to get up a hill. This is my second van with this gearing. Wasn't impressed with the last one either.

Our terrain here is very hilly. No flat areas to speak of so it seems like you are always pulling a grade.

I was wondering how a chip or tuner would work on this van?

 

 

on my 87 conversion van stock 302 and 3.55 rear. it was a dog when i first got it. it only had 94,000 miles on it. i pulled the complete factory exhaust and put a complete 3 inch single exhaust , all the way out the back bumper with straight through muffler. man what a nice running rig it is now. i also drop from a 235/75/15 to 215/75/15 tires.

 

Here's an update ..........I changed the rearend to 4.11 last year. Much better driveability now and increase in mileage. RPM on motor is still only about 2300 at highway speed.