'65 diff X-member crayon markings

[Wayne M.]

Was bushing the baked on dust with one of those brass-bristle "toothbrushes" when I could see characters appearing. Immediately stopped and wiped down with Varsol. Would have gone a whole lot gentler if I knew there was something there. Auto load pic shows rear diff case with matching surface to the X-member. The paper ratio-code tag is 80% gone and the rest is oil-soaked, unreadable and disintegrates to the touch.

The car is a very late 396 with original 3.70 ratio diff (assy. code FA_7_15_65). Don't think the diff or the X-member had ever been removed. I've owned the car for 19 years.

Close ups # 1 and 2 show what I think is "L88" (or else I've got an over-active imagination). I could understand "L78", but that still wouldn't have defined the ratio.

Close-up Pic 1:

Close-up Pic 2:

Was it common to write stuff on this part ? I've heard of F41 suspension cars having "HD" written on the frame X-member just rearward of the diff X-member.

[Chuck S.]

Re: '65 diff X-member crayon markings

Wayne, there appears to be some other things going on besides the apparent "88".

Apparently there is undercoating on top of the markings...my 70 had evidence of the tunnel over the differential being undercoated for sound deadening...it's not in the AIM to my knowledge, but it was sure there; maybe the cross member got some overspray from this process. The usual black primer also appears to be elsewhere, and would be under the markings.

If you're interested, you might try to expose more of the marks by removing a little more undercoating. The problem is that any solvent, including Varsol, that will remove undercoating, will remove wax crayon marks even better. I would probably approach it by using a dental pick or small screwdriver to try and "flake" the aging undercoating off the top of the marks. If the marks begin to come off with the undercoating, I would quit "picking", and come up with another plan.

Nineteen sixty-five L78...now that's a big block to own IMO.

[Barbara S.]

Re: '65 diff X-member crayon markings

Wayne. It looks more like 38 than 88 (?). I'm curious, do you know what job number your car was? It is written in at least two placed on your body: the lower firewall on the passenger side and the rear bulkhead in front of the gas tank. I'm curious if your car is job number 38?

Tony

[Kevin M.]

Re: '65 diff X-member crayon markings

I only see 38 also, the first and second numbers are drawn totally different. I was thinking job number also or ratio, suspension code?

Kevin

[Wayne M.]

Chuck, Tony, Kevin

I tried to be gentle (methanol on a rag) then the small screwdriver suggestion, but everything dissolved or chipped to the bare steel.

VIN ends in ...564. S-body job (crayon) # on this car is "204".

So it will remain a mystery. Thanks, guys.