Hi, I read a nice writeup on this site by Steve on switching , however it was for later models.
I have a 1988 E150 RV Van with a 302 Cu. 3 speed auto with O/D and the total weight is around 7,900 pounds.
I want to put a E250 rear axle and front hubs and switch over to 8 lug wheels. Do I have to change the master cylinder if I get front disc brakes?
Any certain year that is better for my needs?
Also any other info on the change over that I haven't covered.
I want more stability on the road plus the advantage of larger bearings.
I know the E250 tires will have a larger circumference so that in itself may determine a different R&P ratio. Not sure though. Most of my driving is highway 65 MPH.
Thanks for any advice you can give.
GA Boy

 

The highest GVW for an E150 was in the area of 7000 lbs. Are you sure you are running at 7900 lbs? Where are you getting this number?

You would definitely need to change out the master cylinder to match the new brakes.

If you are not overloaded (7900 lbs IS overloaded), I am not sure what you are looking for in stability. The LT tires on 8 lug wheels will give you a harder ride. And read up on "unsprung weight"--heavier stuff on the road side of the springs is generally not good for ride quality or control.

Sounds like a lot of trouble to go through. I'd redo your suspension with good parts (ball joints, tie rod ends, new shocks, etc) to make sure it's tight. Change out the bearings if you want to be sure they are healthy. You can get LT rated tires for your existing 15" wheels if you want a harder "feel". You could buy 16" wheels and run the same tires on your van as would come on an E250.

If you are running at 7900 lbs, you would want to be changing out springs as well as axles, and the lighter E150 frame may be an eventual weak point. If you change the rear axle out, you will likely get a stiffer axle ratio from the E250. You may also need to change the driveshaft for the new rear axle.

Good luck,
George

 

I've gotta agree with YoGeorge here----you're better advised to first renew your existing suspension to like new condition. If indeed you're running 7900# on a GVWR of 7000# that's unsafe, plain and simple. Add in worn parts and disaster awaits.

Seems to me your year E150 was significantly different from E250's & E350's. As mentioned the frame itself was different which would make most suspension parts pretty much incompatible between the different GVWR chassis.

For me running that close or even over a rated GVWR would scare me crazy--wondering what would break without warning first.

Is there a link to this article you mention?

 

YoGeorge and JWA, thanks for the response but none of my questions were answered.
I have been in construction for over 50 years and am thoroughly familiar with GVWR.
It is a figure established by the manufacturer to protect warranties, etc. Any vehicle worth buying will haul much more. For instance my '01 F250 (7.3)pulls a 5th wheel trailer that has a tongue weight of 5,000 pounds.
My E150 RV van also tows around a 2,000poung BAJA.
Back to my original question. Will E250 Front axles fit under the E150 frame?
Will the Rear axle and Diff. fit with only having to cut the driveshaft.
Someone did mention the Master Cylinder would need upgrading, thanks.
BELOW IS STEVE'S POST

Its not too difficult to do the chassis.

The springs and shocks are easily changed. You will need an E250 rear axle and possibly a rear u-joint that can adapt the rearend to the 150 drive shaft. The drive shaft _may_ have to be shortened orotherwise modified. You will also need the front hubs and brakes. To make the brakes work correctlyyou will also need the E250 master cylinder because the E250front brakes are dual piston calipers where the 150s aresingle piston calipers. If you have ABS this is going to be alot moredifficult.

You will need the eight lug wheels and the appropriate "load range E"tires.

Do you know which transmission your van has? A '94 E150 will probably have an AODE but itspossible it has an E4OD. The AODE is a pretty good transmission and might holdup fine under the load but the E4OD is what would have come in an E250. You do not want to try and change thetransmission.

Steve <o></o>

__________________<o></o>

 

Hi GA:

I frankly don't know the answers to your questions and was just trying to vet out a possible "newbie" post that was based partialy on misinformation. We often have a kid stop by who wants to do some sort of major transformation (like converting a van to 4WD) without having an idea of the extent of the modifications.

Given that your van is a 1988 model, it seems like you could sell it and buy a proper heavy duty E250 or E350 that will be a better tool for your intended overloaded use, perhaps involving less money than the changes you propose. Alternatively, could you find a rolled over 250/350 van and swap your body onto the proper HD chassis? (Body swaps have been discussed here--often when someone finds a 4WD rollover or something.)

Trucks are generally overbuilt and will carry more than their rated payload, but I sure wouldn't advise it on a regular basis and would not want to be driving in front of you when traffic comes to a sudden halt. Getting into an emergency situation with an overloaded vehicle may not go well. A 302 is gonna be a fairly weak-kneed engine carrying around 7900 lbs, but if you've been doing that already, you know what it will do.

Good luck with your project if you choose to pursue it. I would definitely advise the sturdier brakes and suspension if you are loading as heavily as you say you are. And absolutely the different fluid displacement would require a bigger master cylinder. From what I recall, the frame on the 250/350 is deeper and probably heavier sheet metal. Once you start changing front suspension, you may need to change out steering box, steering links (taller ride height), radius arms etc. Are spring perches and shock mounts in the same place? Are they sturdier on the 250/350? Maybe someone who has done this will chime in. Any way for you to get hold of the Steve guy that did parts of this conversion?

Your best bet might be to seek out a 250 and start looking at mounting points, lengths of radius arms, etc. My best suggestion is still to seek out a 250 or 350 if that's what you need.

George

 

Not to sound too much like a parrot but replacing the entire van would be my choice. I can't see spending that much money and time to upgrade an '88 E150 when suitable E250's or E350's of that same year or era could be found quite reasonably.

Sorry to intrude and not answer your questions--------I forfeit my right to reply yet again!

Best of luck with this.

 

Gentlemen, I see that I have made a grave error in not telling you that the E150 is a Class "B" RV and I have put some extensive labor and money into it for traveling with my wife of over 50 years. I'm well over 70 but still have my health and have always been mechanically inclined.
I believe that STEVE made his post on this site but not positive. As far a braking, I use a brake buddy in the towed vehicles. I have plenty of experience in 18 wheelers as well as other heavy trucks. Safety has always been foremost on my mind and I adjust my speed accordingly. I added a tray on front for my generator,110volt. And extended the rear (aluminum with styrofome insulation.) for longitudinal sleeping rather than the original transverse sleeping arrangment.
I trust the picture shows up in a decent size.

 

Your project makes a great deal more sense, GA....sorry I could not offer more direct help and when I was questioning your motives had no idea that it was such a cool conversion. Weird that it was done on an E150 and the 302 has to be working pretty hard with all that frontal area.

My first 2 vans were Turtle Top conversions (a '73 Flatnose E200 and an '86 GMC G2500). Yours is a much nicer setup for sure.

If I think of any resources I'll let you know. If I were you I'd go visit some truck suspension shops and borrow some brainstorming time. We are getting 60mph wind gusts right now and if I had something as tall as that, I would absolutely want an E250 or E350 class suspension and brakes on it.

Good luck, and especially with the Baja Bug, that looks like a really fun time. Poor little 302

George

 

Cool Conversion!