Do I need an aftermarket trailing arm crossmember??

[lil_sahara450r]

hey guys,
This is my first thread so dont bash me too hard lol. Ive used the heck out of the search function and couldnt really find a good answer.

I am building the rear of my 66 SWB and this will be my set up: I have installed the CPP c-notches, dominator 2600 air bags in place of the coils, ECE shock relocators, ECE super tracbar, and 2" drop blocks.

My quesions are: will i need an aftermarket trailing arm crossmember? such as the ECE or CPP units? the idea of having exhaust openings is nice, but will i have driveline interference issues? and the salesmen i spoke to at CPP metioned that it will also correct my pinion angle. I am assuming by raising the mounting position of the trailing arms upwards?

Any insight on this would be greatly appreciated guys, y'all have been a MAJOR help in the past several months (not to my wallet tho ). I usually dont post threads though, as 99% of the time the search function answers all my questions. if there is already a thread on this please point me in the right direction. Thank you!

And also, what shocks are you guys running with this set up??

[KQQL IT]

Read up on Super 73's thread he built and adjustable one.
i believe its in the Drag racing forum side.
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[tubbedII]

You don't "need" one, but the benefits are what you've been told plus the added ground clearance since the crossmember is flat with the frame.

You can get by with yours as is by just cutting holes in it for the exhaust to pass through. I've seen the holes reinforced with a small piece of pipe and some just cut and ran. My plan is to just do this with my exhaust and the muffler shop will be doing it all (holes in cross member included).

[gringoloco]

Not necessary, but beneficial. Check out Performance Online. Theirs is cheaper than the competition and they're currently running a 15% sale...

[BMERDOC]

If you don't have ground clearance issues because of the driveshaft hole and you elect to drill the exhaust holes you can break the trailing arm brackets loose, flip them upside down and bolt them in using grade 8 bolts. This mod locates the trailing arm bolt hole higher on the crossmember.

[70-Shorty]

Originally Posted by gringoloco

Not necessary, but beneficial. Check out Performance Online. Theirs is cheaper than the competition and they're currently running a 15% sale...

It looks suspiciously like CPP's item....but yeah, you're right, That's a nice price! It also doesn't suck that POL is MAYBE 35 minutes from me. No shipping!
Tim

[lil_sahara450r]

Ok, so i don't NEED one, but would it be better to have one? i dont have a problem doing it, just really not looking forward to cussing out more frozen up rivits! those things were meant to last lol! with the one from POL being on sale, what would you do? just dont wanna be wishing i would've done it when the truck is complete...

[BMERDOC]

You'll still need to do A LOT to knock in the new crossmember. You just need to figure out the money/time thing. Do you wanna go through the hassle to modify the old one or the hassle of the time/money to install a new one?

[tubbedII]

If the cab is off and you have the $, I say do it... I would...
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[lil_sahara450r]

well the cab is still on the frame at this point. and time really isnt an issue as this is just a play truck for me. the bed is off and all of the rear suspension, just a bare frame from the cab back. but from what you guys are saying, i have two options, 1. modify the original crossmember or 2. put in an aftermarket unit. either way the original one will not work without being modified?

[BMERDOC]

Im not a bag pro so I'll have to bow out now. I don't know how low you'll wind up going. Ground clearance is my main question other than that its up to you.

[lil_sahara450r]

I'm no pro either. this is the first project that i have EVER cut a frame on (thought i was going to puke in the middle of cutting for the notches). and the first time ive bagged a vehicle as well. sure has been interesting so far and cant wait till i get to see it all together again. does anyone know if i will hit the bottom of the bed floor with the diff with this set up on a 66??

[gringoloco]

The stock crossmember will function just fine. You will have a fair amount of work in it cutting holes and rivets to flip the brackets- the only other benefit is ground clearance- just comes down to if you wanna spend the money...

Your diff will hit the wood floor with bolt-in notches- tall bumpstops or a cut floor will remedy this

[lil_sahara450r]

damn... tall bump stops kind of make all the work on the c-notches redundant....

[gringoloco]

Yeah, you'll lose an inch of your notch. That's the least invasive way- the others involve cutting or raising the floor. You may also be able to shave the diff, ala rock crawlers...

[tubbedII]

I remember seeing someone doing a trap door type of hole above the diff (or maybe someone just talked about it)...so when the air is let out, the diff hit this part and it just lifted up on it's hinge, but when you air up, its almost like it's not there. I thought that was a cool idea.

On my blazer, I just cut a hole since it's under the seat you and you can't see it over the carpet. I did cover it up with a scrap piece of dynamat...ghetto I know but no one can see it.

[lil_sahara450r]

thats actually a great idea tubbedII!! havent thought of that! i fugured i would just make a cut out just large enough for the diff and make a cover for it and paint it the same color of the truck (going with tropical turquoise, a 57 chevy color).

I guess i will get one of those crossmembers from POL and install it whenever i take the cab off. it looks like it would be a major pain to install with the cab on. my goal is to basically do a frame off restoration, but just a section at a time. right now im doing the bed, rear suspension, axle, and painting the frame. then i will do the cab, and then the front clip, engine and tranny, and front suspension. my reasoning is when i complete each section, i can drive it for a month or 2 then i can start on the next. instead of blowing it all apart at once and take the chance of loosing motivation or misplacing parts and forgetting how it goes back together lol.

[lil_sahara450r]

what shocks are you guys running with this set up????

[gringoloco]

If you have shock relocators and 2" blocks, you can use stock length shocks and bury the axle in the notch...

[lil_sahara450r]

Originally Posted by gringoloco

If you have shock relocators and 2" blocks, you can use stock length shocks and bury the axle in the notch...

hey gringo! i actually just ordered the monroe 32301 shocks you used in your build up! read your whole build and i must say job well done! snagged the shocks off of amazon for 9 bucks a peice and free shipping! cant beat it! this setup handle pretty well? does it feel sporty? rough? plush?

[gringoloco]

Thanks! Glad to see someone making use of my ramblings It rides and handles well- it's no 'Vette, but better than stock for sure. If I had it to do again (and I may), I would use a 6" Slam bag instead of the 7" Dominators, for a little higher spring rate- it gets a little soft at times. The blue Monroes are awesome- especially for the price- and are what ART ships with their CoolRide kits.

[tubbedII]

A little off topic but wanted to ask you something gringo...instead of swapping bags, could you put in a taller lowering block to solve this issue? I don't know if you're rim size would allow a taller block without scrub line issues, but if it can, wouldn't this result in a siffer spring rate? Since you would need more air in the bag now to get to the same ride height, doesn't that result in a stiffer spring rate?

My biggest reason for asking is I have 2" blocks on mine right now, but I also have a 1" block. I was going to put it on to achieve this even though it won't get me any lower, but I haven't driven it enough to tell if it's too soft. I do want to drive at a ride height equal to a 5-7 drop though.

[gringoloco]

Yes, your logic is sound- that will work, but not for everyone because of the scrub issues. I personally don't like the look of the stock style shock mounts hanging down- I had this setup on my Blazer (3" block w/ 7" slams) and it worked well sitting in the garage- no road time though, so I can't comment on real world function...