Center line to move up In 2nd gen??

[jaws61]

Hey
I"m putting a mustang 2 in the truck, and plan to have the truck lowered. I've been read that guys move the centre line by an inch or two making the wheels look better in the fenders,
I"m just curious on what other people have done and how it turned out?
Right now center line is 27.5inchs from the front of the frame and 15 1/4inches from the back of the first cab mount, both measurements on the drivers side..

[Advanced Design]

A good suggestion is to lightly tack in place, assemble the suspension, then install the front fenders to look at wheel position in the fender well. Then, if you need to move the crossmember fore or aft for better wheel position it is pretty easy to do.

[dwcsr]

Originally Posted by Advanced Design

A good suggestion is to lightly tack in place, assemble the suspension, then install the front fenders to look at wheel position in the fender well. Then, if you need to move the crossmember fore or aft for better wheel position it is pretty easy to do.

What he said.

[Speedbumpauto]

What they said and remember to use allthread or something to mock up ride ht., not hanging ht.

[_Ogre]

i'd rather use a measurement than tack everything in place, build the whole front suspension and then install the front end
only to tear everything apart to weld the x-member in
anything from 7/8'' to 1.25'' is good, i used 7/8'' on truk

[dsraven]

everything they said, plus use the wheels and tires you plan on using when done. a different tire size can change the look. because the fender slopes down and away behind the wheel it makes the wheel and tire look like they are being pushed backwards into the opening the lower the truck is set. that is why it is important to use the threaded rod and washers/nuts to set the ride height you want. be sure to set the rake angle you want as well because it is going to affect the front geometry if the cross member isn't welded in parallel to the ground. the lower control arms should be parallel to the ground at ride height, side to side as well as fore to aft.
if you google image search selectric 59 chev frame you will likely come up with a blueprint of the factory dimensions. the 55-57 stuff is the same except the frame is shorter ahead of the rad supports. the 58-59 frames are longer due to fender differences and a filler panel behind the front bumper. the actual wheel base is the same though.

here is my suggestion for a step by step:
-first do a read through of mustangII geometry so you understand how this is supposed to be when done. try fatman or heidts for tech write ups.

-set frame on modified axle stands, that have threaded rod adjusters in place of the usual sliding upper sections, so the frame could be brought up to level side to side and with the rake angle you like. bolt the threaded rod to the truck frame as well so it is sturdy and non-moving. use jam nuts to keep the rod from moving while doing other work. if you don't have this luxury, improvise with blocks and shims or wedges but make sure it is sturdy when done. some heavy stuff will be removed and installed with all the related grinding, buffing and general movement.
-measure and mark center on all the frame cross members. then run the laser (or string line) down from the front to the rear to make sure the frame you have is straight-front to rear.
-measure from front left to right rear, and vice versa, across the frame to make sure the frame is square, corner to corner.
-remove all the old front end suspension.
-clean area and trim related frame areas to accept the new cross member.
-check to be sure the frame is still level and at the desired rake angle after all that possible movement. adjust as required.
-there is usually some boxing plates to be welded in at this point. be sure to leave ample room for good weld penetration especially if you plan on grinding it all down to look pretty. some guys leave an actual "corner" depression that would be filled in with weld and become a nice rounded frame edge. weld small areas at a time, like an inch or so. move around lots to help dissipate heat and not build up heat in a concentrated area. heat warps. google it for procedures.
-install the new cross member using bessey clamps or light tack welds. use the pivot bolts for the lower cross member as the reference for "level" because the cross member may not be in the same plane as the pivot and that is the part that counts. the bolts can be left not fully inserted and a level laid across them for the side to side check, then the level can be laid across the lower control arm, fore to aft, for that check. a light tack weld would be advised when the cross member is level all directions.
-assemble front end, no need to torque everything up yet, just a mock up. ensure the lower control arms are level side to side and fore to aft. use threaded rod, in place of the coil spring or air bag etc, to keep the suspension from moving.
-install wheels and fenders, then check the "look".
-at this point it is not a huge deal to move the cross member a little to get the wheel where you want it in the opening. make sure to check the cross member for square with the frame. I think they usually reference the old front leaf spring hanger center line. place a square on the frame and bring that line down to the lower edge of the frame, then lightly center punch a mark for future reference. it will also make a difference where the upper control arm is located, fore to aft, at the hinge point on the frame. usually called the "upper hat" mount. this mount is also usually set with a 4deg incline for anti dive angle.
-when you get it all together and like the wheel opening space you can deal with the welding.