i've been thrashing on this 72 dart and things are escalating. i am/was looking to run slower than 11.50 due to no roll bar. that said i'd like room to grow but have no intention to run faster than 10.0. this is snowballing because these cars have no tire clearance. was looking at it real hard and to move the springs into the frame rail doesn't look that hard. it also looks like you "might" be able to get a 10.5 tire underneath it without mini tubbing it which i'd like to stay away from if at all possible. i know it affects weight transfer but to gain some clearance at the front of the wheelwell if i do put the springs in the frame i'd like to move the axle back maybe an inch. the car will be lightend a fair bit but be all steel. it will have aluminum heads, intake, master cylinder, water pump, manual steering, battery/fuel cell in trunk and everything under the dash will be gone. i'm going to take a fair bit of weight out of the car which i'm pretty good at so i'm thinking moving the axle back wouldn't be a big problem. it will have 002/003 SS springs, maybe caltracs later. i currently have a completely new drum to drum 8 3/4, 3.91, auburn sure grip, moser axles under the car. 1" over springs everything's been glass beaded and painted. i ordered a spool for the 8 3/4 but i'm leaning towards putting a dana in the car and being done with it. that way i could sell the 8 3/4 stuff while it's new to offset the cost of the dana. i have a lot of fabricating equipment and have a racer friend that owns a fab shop so i could get him to make the frame boxes. i'd like to put an additional gusset out to the stock spring hanger area so i would have him make the front plate of the box wider to run over to that area. to align the boxes i can turn the ends of a 1 1/2" piece of aluminum bar stock square on the lathe then lay the boxes on the bed of the lathe with the bar stock between them and clamp them together with a bar clamp. for the rear hangers there's existing holes in the rail that it seems people use although they're a touch forward. think they'd still be ok if i move the axle back an inch? on housing width i took some rough measurements but forget what i came up with maybe 46" to the housing ends? i'd definitely do more checking before ordering the dana. i really need some pointers and experience here so i don't screw the job up. thanks!

Your really over thinking this... mount the boxes where
they were before.... use some of the reference holes
in the unibody to make sure they are square to the car
then double check them to the axle... you should end
up with the axle square to the boxes AND the reference
holes..... if you look at the body you will see holes
in the unibody that line up on both sides of the car
these were jigging holes when the car was built

trim the front of the wheelwells instead of moving the rear end back

Why not put in subframe connecters, which gives you a place to mount the front ladderbar mount! Install ladderbars. You will have a great suspension, lighter than the caltrac/leaf deal, it will be ready for a monster tire if you choose to tub it. In the mean time you will be able to use every last inch of wheelwell you now have.

Are you going to run a fuel cell or stock tank? Moving either rear back is doable but may get cozy with the stock tank - the Dana more so than the 8 3/4, especially if the Dana has one of those funky braced cast aluminum covers.

I'd make up some new front spring hangers where there's a stock hole, one above it, and another an inch back, and then another above that, to allow some adjustability, like moving the front of a ladder bar for more or less hit on the tire.

Moving the rear will help with the rear shackle angle to help the chassis rise. Still, I'd make a homemade spacer to put between the body and the upper bracket that supports the rear spring shackle so that the top bolt of the shackle is forward of the lower shackle bolt. That will allow the shackle to arc forward allowing for more rise. Longer rear shocks and/or shock extenders will insure your shocks don't top out or run out of travel as the chassis rises.

I'm sure you're already planning to tie the frame rails together. Bill Reilly's Big Block Dart site has good pics of how to build and install them, and also mini tub info, if you go that route.

Move the axle c/l back as necessary...it's done all the time. You'll be able to fit the common 10.5X28S tire easily. Leave the stock springs in and put cal-trac's on them or change over the whole deal to a ladderbar IMO for the consistency! If your not going to cage it now I'd put a 'legal' and smart(forethought) subframe to include a transverse bar you could later mount the ladderbar brackets and main hoop on. My Your smart for asking.

I just put 002 003 leafs in my demon and I needed 1.5" spacers behind the shackle hangers to get a halfway decent angle on the shackles. If you shim the front spring hangers or fabricate new extended ones I don't see you having much work to do on the back side of the springs. Should be the easiest way to just move back the rear 1-2"?

The guys saying don't underestimate the small slicks/ ss springs w/ caltracs bars setup got my ears standing up, but it seems like once you decide to start welding inboard springs and the like you might as well also consider ladder bars, tubs, etc.

Good luck!

i have no intentions of ever upgrading the suspension to ladders or four link. i think for the 10 second and slower cars a properly working leaf spring car with the right tires should be consistent. i do plan to put a roll bar in it eventually the engine on the stand might not even go fast enough to need it. stock fuel tank will be gone, using a cell. it already has some mediocre weld in frame ties in it and i'm going to leave them there. between the ties and 8 point bar it should be plenty stiff enough for what i'm looking to do. at this point it has had nothing cut out of the car and i plan to leave it that way with the exception of moving the springs into the rail. initial tire selection i'm loosely thinking about is something like a 10.5 x 30 radial slick (hoosier?)

I ran a 30x10.5 on there with moving the springs in. I also cut the rear to ~49" so everything fit like it should. I did not relocate the axle rearward and needed to change the wheel opening to fit a tall tire on there. I squared off the stock wheel wells and put small tubs in it.

i aware of the section width Fred and if it fits at all it would be close. as it sits the wheel well is about 12" wide and i don't know how much "massaging" might get me. i might just get a pair of 9" for now but mount them on 10" wheels so i could go to a 10.5 if/when i do the wheel wells. i want to to get this up and running ASAP and it's tough trying to do that plus build in the ability to upgrade to where i might end up. i'd rather not beat up on the 8 3/4 then try to sell it which means a dana. if i'm doing the dana i have to get the springs in the framerail cause i'm not going to buy a new housing, weld perches on it then have to hack them off and redo it later. if i'm going to do that i should have enough room to use a 10" rim. the tubs look like the more difficult job so i'd like to leave that till later. who knows i might just put the spool in the 8 3/4 for now just trying to think ahead.

I understand setting the rear end back a couple inches but pay attention to the rear shocks as they might get in a bind.

Donald

I had a 1972 Dart with a 440 that I ran years ago, a freind gave me a pair of over half way gone M/T 26x10x15 drag slicks(maybe 26x8x15, I can't remember) off of his street race NOS powered low ten second Mustang. I figure they wouldn't work on my car, wrong, they hooked really good I ran them for a couple of races and switch to a new set of M/T 10.5 x 28x15 drag slicks,I had to massage the front edge of the lower rear fenderwell to make them not rub I would run those 26x8x15 (or tens whatever size they come in) again in a heartbeat BTW, the car didn't run any faster with the new, bigger tires