I am looking into possibly tubbing out my 48. It needs enough work on the rear anyhow, including new suspension etc. I want fat rubber under it. I have 275/60/15bfg's on it now in "roller" status. They clear enough to garage roll, but street use wouldn't even be close. I need all new springs and etc anyhow, SO I am considering a Competition engineering rear frame kit and a 4 link. Has anyone done this yet? Pics would be great. I WOULD like to keep my rear seat if possible. Thanks,Jason

Something similar to this picture.

Ive done a truck. Havent gotten it ready to drive yet, but the rear end is all done. Pretty easy to do, just cut, measure, weld. There are downsides to a 4 link though. If you plan to drive it alot, just "mini-tub" it and stuff in the big meats.

Laine

I've done a couple. It's a fair amount of work but can be done with moderate fabrication skills. You do need a flat and level surface to work on as you will be marking and measuring loactions on the floor. If the floor is not true and level and or the car is not level you will not be able to get the car square. I built a level platform in my garage when I did it. Keeping a rear seat will depend on the size of the tubs you install. If the 275's are as big as you are going I would just move the springs in and mini-tub as already mentioned. That way you can also keep the back seat.
Arno

275/60's are just what I had in my Garage. They fit, but not enough to drive. I looked at the work that was needed to do a mini-tub and figured it wasn't a whole bunch more work. Maybe I am wrong, but If I do the mini-tub, I can gain only about 1.5 inches before it hits the frame.
The other factor is the square tube frame is extremely solid and clean, except for where the bumpers bolt on. About 2 inches towards the front of the car, the frame is kinked. It is very mild and isn't a factor for drivability. I just kind of thought I could clean up the rail, and cut the wheelhouse a little further. If I did the frame kit swap, I definately put Taller by huge tires under the rear. The easiest thing is to get smaller tires, LOL!!!, but it looks soooooo much cooler with wide rubber in the rear.

If I were going to do it, I would bite the bullet and buy the rear section jig welded. I know....more for the part and more to ship, but ALOT easier to install.

What body style is your 48? I can't picture much back seat left if your putting wide tires on the rear, only what will fit between the wheel wells. I have a 48 business coupe and without measuring, there can't be more then 20" from the front edge of the factory wheel well to the back of the front seat. I can't imagine your wheel tubs are going to be the same size or smaller then the diameter of the factory wheel wells. Gene

It is a club coupe. The frame on the thing looks like it is 3 inch?? square tube. I am not sure how to mini tub it without doing anything to the frame it self. I would love it if I could do a mini-tub, but it looks to me like I would only gain an inch or so for the work. Ideally, I would like to end up wit 18x7 rubber in front and 20x9 or 10 in rear. Not really a pro-street build, but one of the modern looking street rod looks with the big wheels. Unfortunaltely, it looks like the same amount of work that it is to make it pro-street.






http://www.flickr.com/photos/8240930@N04/6552400079/

http://www.flickr.com/photos/8240930@N04/6552378477/

How much room do you need to gain? If it is only a couple of inches you could go 1" inside and widen the fenders 1". Still less work than back halving the car.
Arno

I hadn't considered the fender widening. I need about 2 inches. 3 would be safer, but 2 would work. I only have about 1.5 inches on the inside of the wheel to the frame. Only about an inch of that is movable wheel house. The more I think about it, if the rear fenders can be widened, I can do a mini-tub and widen the rear fenders. I could probably play with backspacing of the wheel to get the tire whre I need it to be. The 275-60-15 I have is a good reference. The tires i put on the 20's in the rear wouldn't be much taller and very similar in width.(According to Tire rack's measurements.)
Will the car look ok with widened rear fenders? I don't want it to look like a so-cal beetle with flares.LOL!!

If you modify the wheel opening of the rear fenders, you can put some pretty wide tires on that body without cutting much.
In the past I have simply cut the wheel opening round to clear the tire, and I have cut around the original opening and raised it up on the fender to clear the tire. The width of the rear axle your putting under the car, and how low you want the rear of the car to be, will make a difference how wide of tire will fit.
The rear tires on my coupe have 8" tread surface on the road. They are the same 235 R/ 75 x15 Michelin tires as are on the front, mounted on 70s Mopar 15" x 6 1/2" steel wheels (not cop or anything special). The rear axle in my coupe is from the 90 Dakota and has 5 on 4 1/2" bolt pattern with 3:55 limited slip rear gear. I have opened the wheel openings with a round cut slightly larger then the tire diameter. Though my car has the full Dakota frame, the wheel wells are original to the 48 Plymouth (the Dakota rear frame gives a lot of room to move the inner wheel tubs, but requires extensive rear floor modification). I have about 1 3/4" sidewall clearance on the inside of the tire to the inner wheel housing, and there is about 1 1/2" to the widest point on the outer fender. These rear fenders curve in at the bottom quite a bit, so mud flaps would probably be wanted if you were concerned about tire spray, that is not a concern to me. I'll try o post a few pictures later. Gene

Keep in mind, my car is suppose to represent a mid 60s dirt track car. It was a rusted out pile of scrap I put on a Dakota frame.

Hacked up fender.

Inner wheel housing to tire clearance. This is looking up from behind the passenger side tire. its kind of hard to see, but to the left of the tire you can see the bottom of the inner wheel well lip.

For reference, this is the view from the front. Understand, there were no rockers remaining on my car, so I just ran the new metal down under the car. The piece my side kicker bar attaches to is a filler panel, the bottom edge of the leading edge of the fender is very close to where it would have been originally. you can see how the tire sits compared to the rear fender in this picture. Gene

on my 48 plymouth I cut the stock frame rails before the leaf springs and added a cross member of 2x4 box tube and moved the rails in 10" a side if I remeber right the stock rear tubs also got moved in I will see If I can find some pictures