funnycar crank centerline to rearend alignment problem

hi all!
this question might seem a little stupid,but when setting up the crank to rearend alignement,i see a big difference between the old chevy setup from the previous owner and my KB hemi setup.
this is in a 118in wheelbase logghe bros funnycar chassis.the previous owner was running an all steel injected BBC/glide combo,with a solid splined driveshaft to the female coupler on the rearend(dana 60 floater).
i bought the rolling chassis with the intention of running it with a KB hemi/clutch/lenco setup.
my trick bellhousing has chevy/hemi holes,so the same crank centerline(right?)
so when i bolt the bellhousing to the chevy holes in the midplate,the centerline is all wrong(rearend is pointing "upward")
setting up the alignment from the rearend sets the bellhousing about 2 inches higher on the engine midplate,and the front of the hemi is pointing so high upward that i cannot fit the oil pump as it does not clear the upper chassis frame rail.
all this was done with the chassis on stands.
so i'm wondering if i'm supposed to take into account some "chassis flex" with the full engine/trans weight as a baseline to set the centerline?
or is the centerline in the chassis supposed to remain the same,with or without the engine?
i hope that my explanation was clear...i have pics i can PM for anyone needing them...
thanks in advance
cyril

 

I believe the early hemi, 392,354, etc have the same crank centerline, not the 426 style,..\
Also an old logghe has suspension in the rear and front try loading the chassis/ car up with the weight that is needed as Run ready ..???

Another possibility,..Did you actually see this car with the other guys motor combo set up in it did it run.?? was it a running car, this is a long shot but, could it have been that the drive shaft from this other guys deal wasn't aligned up perfect..????

 

alignment

If you are sure that the rear is square, you can always re-ream the rear end plates in place with the mid plate in correct position. You will have to use larger bolts.

 

The engine to rear end alignment should be the same whether the engine is in or not.

 

thanks a lot for all your answers!
this is a chassis from the 70s with torsion arm front suspension and solid mounted rearend(plates are welded to the housing)so my best option is to work from the rearend plates mounting holes position.
if a crank to rear centerline is really "off",there should be unusual wear marks on the female coupler splines(i think?),and they look right on mine.
this is a car that used to be run with a hemi,(maybe an early one,so no clearance problem with oil pump!)and a plymouth satellite body.
thanks again for all your answers!
cyril