Custom 4 bar differential mounts, designed and made to suit custom applications

41 Willys coupe on display at the Sydney Hot Rod show, all bare steel body with a Kustom Bitz gasser modified chassis under it.

You would think a supercharger kit install would be pretty simple .... well no, is the short answer. A wise man once told me a 'kit' is not a solution.  And having worked on a few of these set ups now these words keep ringing in my head and I remember this old man who at the time I didn't think was that wise at all .... now I am older and I see.   In this install I had to port match the heads to the intake as there was a substantial lip into the head port because of the large intake manifold ports. If not corrected would have led to fuel puddling and fouled plugs and drivability problems that would have been hard to diagnose once assembled.  Also the distributor hole at the back of the manifold was off centre and way too big for a standard chevy dizzy and any aftermarket dizzy too. So I had to make a boss to take up the slack and provide a stable boss for the dizzy clamp to work properly.   To add to the woes, the engine assembler failed to pick up that it was a tall deck block and required a longer oil pump drive shaft .... that was hard to diagnose when a new engine loses oil pressure for no reason.   I got there in the end with modded accelerator links, better fuel line route, boost referenced carburettors and a proper harmonic balancer for a blower application.  The install was challenging on this one but the end result was a sweet running engine with monster amounts of torque to hall this heavy full size sedan around the hills .... and cool looks of course.  

41 Willy Coupe chassis fabricated to original dimensions yet extra strength provided in the depth of the chassis and via tubular centre X member and many tubular cross members to take the weight and torque of a big block Ford drive line.  This chassis will have an original steel body fitted to it and the owner wants the whole car to resemble an early 60s drag car, right down to the rear radius rods that look like ladder bars, however it has to have nice street manners and pass ASRF construction guidelines for safe street rod engineering.  Now many may argue a leaf sprung front end and rear end is not the best handling street car and I would agree, but there are always trade offs for the look you want and the right combination of parts installed with the correct geometry can still yield a very nice driver with a really cool look.  When driven responsibly this 41 Willys will provide hours of enjoyment for the owner cruising around.   Chassis by Kustom Bitz [our custom designed rails], Engine Ford Hemi V8, T400 auto, 9" diff installed on leaf springs with diff housing floaters designed by Kustom Bitz for street use [so we have flexibility and suspension give], Super Bell front I beam with disc brakes cleverly mounted to parallel leaf springs without any mods to I beam and not relying on welded parts.   See our section on Hot Rod Chassis construction for more images of our various Willys Coupe chassis that Kustom Bitz has built.  

The Toyota Crown ute is progressing along, the body is fitting the modified original chassis and this is how it will look when it's dropped ... I think it has the right stance ... The framing you can see is holding the upper body together as the floor and lower sections are rusted away and have been cut out, then to be completely refabbed by us.  The frame allows us to lift the body on and off as we please during this stage.

Kustom Bitz just completed a 35-41 chassis, stepped up at the rear and a reversed centre X member allow this chassis to sit 40mm off the deck. It runs a Rod Tech IFS, big block chevy and L80E auto, a 9 inch diff with floating hubs, all on modified original rails. Kustom Bitz has developed our own boxing plates that suit the original rails near on perfectly. Original Ford rails are curved from front to back there are no straight sections, so to get something that fits right we had to jig the chassis up and map them out.  This is what we do, when it just needs to be done right to make it a well engineered car.  This allowed us to make a nice transistion for a high step at the rear. We have designed in 6 inches of travel at the back, so this car can have a normal, almost stock ride height then dumped to the max when parked.

'67 Toyota Crown ute chassis build is going well. Got the LS engine and 6 speed manual box in place and we can use all the orginal serpentine pulleys, brackets etc. The narrow wheel track on the Toyota called for a tailored solution when it came to the front end.  These old Toyotas dont have service parts available any more so the front end had to be changed, so that made a brake upgrade alot easier too. We run R6 air bags from Air Ride sitting at a ride height of 6" for the air bag so got plenty of air volume in them for a good ride quality and a full length travel shock absorber so we get proper rebound tuning, along with a power steering rack.  So at the sill [belly of the car] we get a 5" ride hieght with a 4 inch drop, this thing will look great.

Recently in Victoria some engineers have called for the upper and lower mounts for the rear coil over shockers to be a double shear bracket.  The thoery is that the bolt has too much twisting force on it and it will break. Well thats why on Hot Rods we use a 5/8" grade 8 bolt in a single shear bracket application to over engineer it so it does not break. A typical OEM application uses a 1/2" bolt in a double shear bracket. However to please the engineer we have thought out a simple plate kit that can be welded in on the upper mounts as you see here to satisfy their requirements and should fit into most applications without too much effort or rework.  We have a lower mount bracket nutted out as well.

So many hot rod shops don't install proper bump stops.  In this instance we had to rebuild the shocker mounts on the diff as the rear end was bottoming out on the shocker travel becasue it had no properly designed bump stops in place. So the shock absorber mounting bracket was absorbing every bump when the suspension bottomed out, easy to see why both mounts broke. While we were repairing the diff I made a simple yet effective progressive bump stop that is held in place via the U bolts that hold the diff to the leaf springs. It turned out a very successful set up. This is yet another example how Kustom Bitz can sort out problems on your custom car or hot rod, its what we do.