find some donor station wagon sprigs extra spring rate helps
you can rebuild yourself put in plastic interliners they work real smooth
you can also put in front torsion bars from a late 70s donor expecially a wagon PC ot trailer tow
then when you have the larger front bars put in a rear sway...
Ford supplement works best for me
narrower drum to drum makes wider wheels easier
u joint yokes vary
somehow I think very tall ratios may take a different pumpkin (the pinion offset is different) but I may be wrong so check may be a brand x see the link above and study
I had both 65 and 66 Imperials tw0 73 New Yorkers, 69 Polara 2 door 59 Imperial etc
one thing not mentioned is that the converter and input shaft may be different and may have been changed
if you rebuild the 65 small input tran go to the later trans and converter
pistons are much harder to...
start with what monc440 said above cc your heads
choices
440 6 pack pistons at 0 deck with a "D" dish milled to get the cr you want maybe a 100 cc dish
KB quench dome pistons with the dome removed with dish you want for your fuel too bad no e-85
with a 9:1 motor Iwould run Howards 256 @.006...
find some sw leafs getsomelate 70's torsion bars from a sw orcopcar get a cordoba rear sway only after the heavy front torsions wider wheels for radial tires handle like a sportscar
well knon that the specs in the book are .001off for the #3 i had atoolfor that but you can make a reamer out of a straight old cam just kut some groves in #3 square put in while rotating and it will clearance #3 you can then use dykem and a bearing scraper me x factory zone rep
transgo reprogramming kit, level 2 (tow) for heavy car you will also get their tech line
good ideas above, start by adjusting kickdown, use atf plus 4 (change it TWICE unless your converter has a drain) adjust bands while pan off
use the larger late model torsion bars, especially with radial tires, wider 15 inch wheels, make it handel
you can use a cordoba rear sway AFTER you source the bigger t bars
you can swap your later valve body after you clean it an I recommend a transgo shift kit, an keep your part throttle kick down, well worth it to use the later valve body
no time to read all the posts now but I'd have someone follow me and do the on and off the gas test looking for smoke that would most likley be rings
then change the valve stem seals they have to be toast you can get a tool to do it in the car while you have your springs off check each...
There is a reason Mopar went to 3/8 and sometimes 1/2 inch o diesels ou need good flow no sharp bends and for those with OD trans go 1/2 put larger threads in trans case and larger fittings when you have it apart really helps those trust washers I converterd to straight cut gears best...