back halfing/rear subframes

[ProStreet83C10]

hey guys, im intending to back half my truck with a rear subframe/clip for a pro street look but im not sure how to go about it. I have some subframes picked out from chassis shops, but how does one go about installing a whole subframe into a pickup - or any vehicle for that matter.

[djracer]

S&W Race Cars makes some nice rear clips. It should be pretty easy to install.

[ProStreet83C10]

right, thats actually one clip ive looked into, however its for an 88-98, but i figured they could custom make one for my 83.

so how would one go about welding this to the existing frame and making it AS STRONG if not stronger than the original frame?

[raceman6135]

Here are the instructions for the 1988-97 C1500 ladder bar welded rear frame package. It's fairly detailed and should help you:

http://swracecars.com/Files/pdf/10_506.pdf

[BigDan3131]

For one thing the truck has to be completely level before you start chopping away or welding in the new rear frame.

[Marv D]

Originally Posted by ProStreet83C10

....so how would one go about welding this to the existing frame and making it AS STRONG if not stronger than the original frame?

Aside from some big ol honking C channel capable of overloading and not buckling..... the stock frame is really pretty flimsy. Give it 40-50 years and you can jack up one corner and not disturb a full cup of coffee in the cup holder LO, OK really the early frames (riveted not welded) get pretty sloppy. Most of the backhalf kits are 2x3 box tubing that may be thinner wall, but if the frame and roll cage are installed correctly,, it's MUCH stronger than the C-channel stock frame. But the cage is an intrugal part of the strength.

Here take a look at this thread
http://67-72chevytrucks.com/vboard/s...d.php?t=479855

I guarentee when the chassis is done and the cage is in, you could stand this truck on the rear bumper and not have any flex at all.

Probably the hardest thing you'll do is take the sawzall / cutting torch and make that first cut. It's a bit un-nerving to say the least.

And Dan is DEAD ON!!!! your concrete floor is not not not not NOT level. I don't care WHO did it and or how you've checked it. NEVER trust measurements up from the floor unless there is two big solid I-beams sitting on it to measure from. If you want to to be perfect, a water level is simple to make, 20' piece of clear plastic hose, fill it with water and stretch it out. Water in that hose WILL be exactly level at both ends. THAT you can trust! You can buy the hose and rubber plugs for the end at ACE for around $20-$30,, stretch it out, uncap the ends and the water at both ends is a perfect level reference to measure from.

[ProStreet83C10]

i can tell ya right now my floor is NOT NOT NOT NOT NOT level. So your saying that if i install this rear clip as well as a cage, it will GREATLY strengthen my entire frame front to rear? Now, where could i go to find a true level floor at? it sure as hell isnt my garage floor.

[BigDan3131]

Well...maybe you should start looking for a local chassis shop to at least install the main frame rails and cage. They might and I mean might have room to let you finish it yourself there if they have room and you ask nicely.

[ProStreet83C10]

well, i had e mailes S&W about modifying the 88-95 ladder bar rear frame they have or custom making one for me and this is the reply i got....

Hi Zach, We would not be able to do that. You would have to make a new jig for the frame. You would have to use one of are universal frames. When you are ready to order that give me a call. Anything else we can help you with let me know. Thanks!!!!!!!!!!!!!!!



RANDY KRAUSE

S&W RACE CARS SALES

610-948-7303 X115

rkrause@swracecars.com

[Captainfab]

Try contacting Art Morrison. They should have a rear subframe to fit your truck. Plus they are really good guys to deal with.

http://artmorrison.com/homepage.html

[ProStreet83C10]

ok sent them an e mail, will reply back when i hear from them

thanks guys!

[BigDan3131]

If Morrison doesn't have one Chris Alston might too.

[blackedoutharley]

These should be a bit closer to you:

http://www.timmcamis.com/

http://www.jerrybickel.com/

http://www.jerryhaas.com/

Neither of these guys are cheap by any stretch of the imagination though.

[C-10 simplex]

Does a pickup really need to have it's frame narrowed in order to fit very large tires in the rear?


In my opinion, no.

[dbmx66]

i have 33x19.5s on, i have about 6-7 inches from inner besides to sidewall and about 2 from frameto sidewall, on 15x15 rims. you could easily stuff 33x22.5s my inner beside is hacked out, but still.

[Super73]

Originally Posted by C-10 simplex

Does a pickup really need to have it's frame narrowed in order to fit very large tires in the rear?


In my opinion, no.

It's not always about fitting a tire. In some cases it's a weight issue. Or a suspension geometry issue. Or even putting the truck o the ground and keeping the suspension usefull. All three of thos reasons are valid and add up to my back half.

[BigDan3131]

Originally Posted by Super73

It's not always about fitting a tire. In some cases it's a weight issue. Or a suspension geometry issue. Or even putting the truck o the ground and keeping the suspension usefull. All three of thos reasons are valid and add up to my back half.

Or for the other reason getting to hook far better than a stock suspension might allow. Besides the fact that a narrower rearend is better with wide tires, having 6-8 inches of backspacing is a load I would rather not have. 4.5 inches? much better, with less flex on my axles and less strain. The rule of thumb for drag racing I have always been told is to run the narrowest tire that will hook.

[Super73]

Dan,

Most of the trucks on this website arent fast enough to be beyond the limits of a 60-72 rear suspension. Myself included. Obviously the original poster of this thread doesn't have that same rear suspension, but could technically go the Caltrack route with great success.

As far as the width of the rear, I will agree that a longer axle might be more likely to twist, but a deep dish wheel also puts a lot of stress on the axle ends and bearings. The wheel becomes a lever, and the deeper it is, the longer the lever is. Just food for thought.

[KQQL IT]

A 15x10 with 3.5" bs vs a 15x15 with 8" bs would side load bearings less than the 10".
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[ProStreet83C10]

found a clip from morrison for around 3500 bucks

[RICKSRAT]

Check out S&W Racecars they don't list a specfic kit but if you call they may be able to get a kit for your app. I used them before with good success.

http://www.swracecars.com/index.aspx

[RICKSRAT]

Sorry just read 2nd page, looks like S&W was already mentioned. You may need to speak to someone else there. I worked with Don @ S&W after the original roll bar they sent me was a really bad fit. I sent them some measurements for a new main hoop bar and they made it good. I bet you could use one of the universal frame rails they carry and it will do what you need.

[mbgmike]

We charge about $6500 to do this kind of work just for info.. but that is all hand fabricated by us. No Kit. We sell other companies components like Alston etc. but we like doing them custom and you get exactly what you want and is strong Just remember if you decide to have a shop do it be carefull of low price quotes. Some do that just to get you into the shop and increase later.

[Super73]

Just an FYI, you can find good chassis guys at a resonable price. I will have between $3,000-3,500 doing:

Full 10 point CM cage 8.50 cert (Just need to have it certed, roughly $300-500 around me)
Custom round tube CM back half
4-link (that's install plus me buying the competition engineering Magnum 4-link kit)
Double Adjustable Koni's (Found used/rebuilt with receipts)
Panhard relocation

My guy has a day job and does it at home. This keep his overhead down. The only down side is it is in his spare time. Not a big deal to me as I know it's getting done right.

[shortbed70]

Level your jack stands before you cut and or make a frame jig that is level then cut.. Measure 10 times then measure cross ways then cut.
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