I recently installed a Mustang II front end from Full Tilt on my 41 Ford Coupe. We started with a 41 ch***is. My problem is the track width is a tad too wide. I've got 2" dropped spindles, GM calipers, 15x5 wheels with neutral backspace and 205/75 15 radials. The neutral backspace is all I can get before I run into the caliper. Short of tearing the tophats off, and repositioning the lower A arms, does anyone have some thoughts for me. Will a Mustang caliper allow me to add more backspace? Narrowed A Arms don't seem like they will work either. The upper ball joint clears the tophat by less than 3/8 inch. I've got to get to a least 2 inches narrower. - Maybe more than a 'tad' ! Thanks
Dude that's usually the opposite case. Was this the universal style kit? What is the measurement from hub to hub (rotor to rotor)?
Something seems weird here. My 41 coupe with an unknown kit from the 80's ran 15X6 Torque thrust with no problems. Later I updated it to TCI tubular arms, not narrowed and again no problem. 41-48's are pretty wide cars. Sorry I can't be of help, but something seems wrong.
I think you should be asking Full Tilt. If they sold you a Must II that was to wide for the car, did they know what car it was for?
I don't understand your comment about "neutral backspace." Measure the backspace - it'll probably be 2 1/2" to 3" for a typical front wheel size. You're probably dealing with a later caliper than is used on the earlier solid axle Fords, but there are no fitment problems with them. Both setups I've been involved with - Camaro and the larger sized Mustang calipers on solid axle Fords fit with 14" wheels that have about 2 1/2" backspace. The Mustang comes close, but clears. The smaller Camaro requires a bit of grinding in a couple of small protruding areas and it has even more room. I'm wondering if your caliper brackets are flat steel and perhaps they should have a step so the calipers sit inward toward the center of the car? Could be as simple as the calipers are in the wrong location. Along these same lines, if the caliper brackets are bent could you have them backwards? 5" x 15" bolt pattern sounds strange unless you have a special Mustang 2 rotor. Most of the aftermarket rotors for the Mustang 2 are 4 1/2" Ford or 4 3/4" Chevy patterned rotors. Fwiw - backspace is measured by: A straight edge across the backside/inside of the wheel at the rim. Measure from bottom edge of the straight edge to the wheel mounting flange. Tell us what you come up with and what year etc. caliper you have.
I think he may mean neutral offset, where the hub mating face of the wheel is dead center, so that the front side and back side setting are the same. Going from that hypothesis, with 15" x 5" wheels, which are going to be around physical 5 7/8" wide - let's say 6", the suspension width hub to hub should be 6" less than the the outer rim edge to outer rim edge measurement (add 1 1/4" for outside tire to outside tire). It seems mighty wide to me too and begs the question, for which vehicle was this Mustang II cross member originally intended? GM calipers should push the hub face out maybe 1/2" per side more than stock Mustang II calipers. ECI have a brake kit that does not widen the track - uses 1978-81 Firebird rear rotors. Going to Mustang II calipers is a downgrade and will reduce braking ability significantly. Pix would help.
what is the distance center to center of the lower A-arms mounting holes in the crossmember? i believe a stock mustang II is 26"...someone tell me if i'm wrong
21.75" center to center on the lower control arm mounting holes. 13.25" from the bushing to the center of the ball joint on the lower control arm.
i haven't messed with enough of them to know for sure how wide they are off the top of my head...thinking about it now the one i put in a `49 Ford was 22 we now know what stock original Mustang II is. i know some crossmember manufacturers make wider ones and narrow ones. amaralcf needs to measure his...then talk to Full Tilt
Fatman Fabrications website shows 56 1/2", 58 1/2" and 60 1/2" wide measured hub to hub kits are available. 41-48 ford use 56 1/2"
The 41 is slightly narrower than a 42-8. I've seen the Heidts set-up on a 41 that looked to wide also.
Hey Guys, Thanks for the input - Here's some clarification: By Neutral backspace I meant dead center. Technically, if we call it a 5 inch wide rim (yes it's going to be actually wider) then the backspace is 2.5 inches. And the general feeling I'm getting here is that I ended up with the wrong kit from Full Tilt. I'm believing that to be true. A 41 track width is supposed to be 54.5" I'm at 57" I did call to Full Tilt, still waiting for a call back! So the moral of the story: stay away from Full Tilt!
A little more clarification: the wheel size is 15" by 5" tire mount width. The bolt pattern is a standard Ford 5x4-1/2" It has (what I think are) 11" Mustang II rotors with GM calipers. The caliper bracket is flat. I'm not sure if stepping the bracket will work. The caliper is now centered on the rotor. I'm going to post some photos this afternoon, some of you guys are going to recognize the project. And more of an explanation of the steps we went thru to get close on caster angle.
Here are some pics of the Mustang II front end. I mentioned that we had camber problems when we mounted the upper and lower A Arms. The lowers where almost an inch shy (inboard) of anything close to correct. We had to move the lower A arm out to get it sort of right. In addition to that we slotted the Tee bolt groove on the top hat almost 3/4" inboard, so we could move the upper A arm inward. With both corrections we near to what the real camber will be. The crossmember sent us dropped right between the rails with no problem. I'm just wondering if we got a mismatched set of A arms and the wrong tophat? Take a look
It may be the pictures but your wheel offset looks negative. Usually the rotor is inside the wheel hoop and not exposed. Also apears to have negative (leaning in at the top) Camber. Also, the air spring toughing the upper ball joint WILL FAIL. The spring should never ever contact anything.
yeah , what Polacko said... you got some odd offset rims there. what did the wheels come from? I have 14 x 7 wheels that clear my 11" brakes. I'm thinking you have a wheel made for a non disc brake application
The wheel offset is neutral. I just measured again to be sure. I think the narrow 5" rim makes it seem negative. We haven't even attempted to set castor angle yet. You are right - it's way off. The camber is probably nowhere near correct either. We're just trying to figure out how to drop 3 inches off the track width. Nothing else is set up for real.
Oh - and we are going to address the air bag. The top ball joint is going to make it blow in no time. Right now we have a spacer on the lower A. We're going to move that to the top hat. That will get the bag away from the upper joint.
If you moved the lower A Arm out, you most certainly will have a bump steer problem also unless you used a spacer to move the tie rod pivots at the end of the rack outward an equal amount. And I agree, the photos don't make those wheels look anywhere near a zero offset.
My dad has a '41 Ford sedan and has the exact same problem! He has a fatman front end with two inch dropped spindles and one coil cut off the coil spring. It looked great, but the tires rub pretted bad. So he ended up having to put the stock spindles back on. As previously posted I have also heard that the '41 is narrower than a '42-'48. They also made multiple front fenders for '41. I know there are two and three piece fenders, with small differences in width.
I've never heard of a difference in width between 2 & 3 piece fenders. As I recall 2 piece fenders were early production and because the bottoms were weak at the narrow spot Henry made the bottoms 2 piece later. In order to run low a deep backspace is needed. Mine is Nova subbed with 1 1/2" narrowed A-arms and I run a 6" wheel with 4 1/4 backspace and a 195/65 x 15 tire
there is something wrong with the wheel offset, or the rotor width. that rotor should be tucked inside that wheel more.
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