Cummins 5.9 L swap

[seamus]

No kidding digging up the dead ones!!

[gotmike]

soooo.... when you shorten your frame... how are you doing it?

i cut mine diagonally across the frame and removed a section then heavily fish-plated the seam... it was later suggested to me to make a notched cut that looks like a square fishmouth and remove/re-weld the section that way... so i was curious what method you were going to use... or were you taking a different route?

[seamus]

I made a very long diagonal cut and removed 29 inches ( i think it has been a while) My best friend is a structural welder. He put the halves back together , after the test fit for the body he will fish plate the entire area. Then he plans to box the center section and install a custom crosmember. I need the crossmember to mount the tank and possibily hold the battery box.
Keith

[seamus]

when they shortened the frame of the c10 chev on Trucks they made a z cut straight down about 1/2 of the way then straight back for the lenth of the section to be removed and then down again to finish the cut. When it was all don they fish plated the entire area. They said it was the prefered way to shorten a chassis. But my buddy says it is over the top. What you did is fine!!

[seamus]

What year was your dodge frame?

[gotmike]

mine was a '92... i shortened it 22" if i remember right... i removed the section between two cross members, but didn't remove the cross members... so i have a cross member directly in front of and behind the welded area... and a 3/8th's plate for a fishplate... and i welded it all myself... it held up even when i shattered the pinion gear in the dana 70... so i'm fairly confident it'll hold up to whatever i put it through... the only bad thing about it all was the fuel tank issue... i didn't have a fuel tank that would fit so i had to re-route the fuel lines and stash the fuel tank in the back of the jeep since it was my daily driver... then i found a fuel tank in a friends scrap pile that fit perfectly between the frame rails in the rear and plumbed into the jeep filler neck... i cut a 6" hole in the top of the new tank and then cut out the neck for the fuel pump from the plastic dodge tank... then i bolted the plastic to the metal tank and put the dodge fuel pump into the new tank...

[seamus]

What did you do about body mounts, use / move existing fab your own? Do you have photos?
I was considering having a local shop fab mine up using my cardboard templates.

If you have any advice on this I would love to hear it.
Keith

[gotmike]

i fabricated my own... i used 3" channel and notched a 90 out and folded it over to make an L then i bolted it to the frame and welded it as well... i cut a hole in the short section at the proper distance away from the frame and used the dodge body mounts since they fit into a hole and have a puck under them... bolt them to the body first then use jacks under the body seam to lift/level the body compared to the frame and make sure it has the proper clearance all along the frame once it's set tack it into place then try and drill a hole through an already present hole in the frame and through the new body mount... bolt it in place and then stitch weld it one inch top and bottom of each side... this will allow for some flex without breaking and the bolt will hold it to the frame relieving some of the stress on the welds... on the back i just used an existing hole that lined up with a cross body brace and put a bolt straight through with a hockey puck in between...

[jaber]

Awesome job guys. I've been watching these threads for years now and am waiting for a diesel to fall out of the sky for me, LMAO.

Thank you for sharing....

[Ted Wendel]

got any pics of the heater box swap im putting a 500 cadillac into a j-20 and it does fit between the heater box and brake booster but i wouldn't be able to get the valve covers off or if i tried to use tall valve covers tehy wouldn't fit at all?

[Eugene 1]

i fabricated my own... i used 3" channel and notched a 90 out and folded it over to make an L then i bolted it to the frame and welded it as well... i cut a hole in the short section at the proper distance away from the frame and used the dodge body mounts since they fit into a hole and have a puck under them... bolt them to the body first then use jacks under the body seam to lift/level the body compared to the frame and make sure it has the proper clearance all along the frame once it's set tack it into place then try and drill a hole through an already present hole in the frame and through the new body mount... bolt it in place and then stitch weld it one inch top and bottom of each side... this will allow for some flex without breaking and the bolt will hold it to the frame relieving some of the stress on the welds... on the back i just used an existing hole that lined up with a cross body brace and put a bolt straight through with a hockey puck in between...

What about A Ramcharger frame? aren't they close to FSJ size?

[j2sax]

Mileage with 6BT frame/spring issues

Well, it looks like this may be the route I am taking if I score a 90 model Dodge I have my eyes on.

For those of you that have gone with the 6BT, what has your fuel mileage been like? Is there anything you wish you had done differently?

How's the stock FSJ frame holding up?

You noted that there was some spring sag, but there were no updates after that. HOw has that worked for you? I have set of Rusty's 4" on the J20 this will be going in... is that enough to deal with the oil pan clearance issues?

I am sure I will read over this and other links numerous times!

Have a great week,

Jesse

[jeepmj_tj]

i'm getting 20-22 mpg out of mine empty. thats even around town. worst tank empty has been 19. towing my jeep in the mountains its been getting 15-16.


i am using stock 8400 lb j20 springs SOA. they have sagged some but the ride is real nice with the weight of the motor. i'm running 315's on h2's could probably clear 37's on the road.

one thing i need to do is try and fit a front sway bar back on. the stock one hits the oil pan pretty bad. possibility that I can make some drop brackets for it and get it to clear the pan if it doesnt then interfere with steering box.

[rustywagoneers_com]

What radiator in yours Jeep MJ/TJ?

OP cherokee appears to have stock FSJ radiator....

[J10Mike]

Wow...Cool old thread. I forgot about this one.
These CTDs don't run very hot. A stock FSJ V8 radiator should work. I'm not sure about a stock I6 radiator though.
In my RC 4bt conversion, I'm keeping the stock radiator. Also, chances are that you will need a piece of cardboard in front of the radiator during the Winter. I have to do that in my 01 CTD Ram to get some decent heat.