A500/A518 conversion/fitment questions

[Mike DC]

                      
Dealing with a '66-70 B-body retrofit.  
I know this subject has been done to death on many threads.  


I know the basics.  
No O.D. Torqueflites were produced with B/RB bolt patterns.
None of them will fit an old B-body without some hacking work around the T-bar crossmember.  Getting ideal driveline angles means SERIOUS hacking/fabbing.  
The O.D. trans pans were deeper too, because of the valvebody inside being lower.  



--  How much of an issue is the trans pan depth?  

Assuming you're willing to do the SERIOUS hacking on the car to get good factory-style driveline angles, how much deeper do the A500/A518 pans still hang down than stock?  (One person's "no big deal" is another person's big deal.  Does anyone have figures?)  Can anything else be done about this, like messing with the trans internally and retrofitting an older shallow pan or something?  




--  Is there any reason why a smaller A500 can't be used on a B/RB instead of the A518?

Yes, I know the A500 is based on the little 904 Torqueflite and not the big 727.  But drag racers have been putting beefed-up 904s behind B/RB motors for decades.  (Less weight, less parasitic drivetrain losses, lower gears.)  It seems to me like the same gains should apply to a street car just as well.  A street cruiser's tranny would be hit with less shock-loading than a drag car anyway.  

Since either O.D. tranny needs the same bolt pattern mods to fit a big block engine, why not run a beefed-up 904-based O.D.?  I've read that even the added 4th gear assembly on the back is basically the same between both sizes.

 

[flyinlow]

I had a Mopar chrome deep pan with drain on my 727. When I put my A518 in my '73/440 I used this pan instead of the stock 518 pan. About the same depth 2-2.25". Already had the temp  sensor and was chrome of course.  About a draw on ground clearance: headers, trans pan, or crossmember . A 2X6 just brushes the drain bolt on the pan and the right side header. With the car empty. Don't drag .
 
A 500's are lighter and might have a lower first gear? I went with the 518 out of a 1 ton van. Bigger is better, right ?

I used a Ultrabell that was for a 727 TF to BB Mopar. Not sure if it would fit an A500 pump.  

Don't know about the O/D unit.

[cdr]

NO LOWER THAN my headers

[Cooter]

                     





--  Is there any reason why a smaller A500 can't be used on a B/RB instead of the A518?

Yes, I know the A500 is based on the little 904 Torqueflite and not the big 727.  But drag racers have been putting beefed-up 904s behind B/RB motors for decades.  (Less weight, less parasitic drivetrain losses, lower gears.)  It seems to me like the same gains should apply to a street car just as well.  A street cruiser's tranny would be hit with less shock-loading than a drag car anyway.  

Since either O.D. tranny needs the same bolt pattern mods to fit a big block engine, why not run a beefed-up 904-based O.D.?  I've read that even the added 4th gear assembly on the back is basically the same between both sizes.

 

I love it when people attempt to say that their ride will never see any 'Track time', when the reality is, they will beat the piss out of it WAYY harder than any 'track time' the car might see, on the street.

Yes, there are 904 TF trans' that will live on the track. However, have you priced some of those 'Race' 904's? Damn! Only  a few factory  parts remain inside in order for it to live at the BB power levels.

Yes, it would be cool to have a '904' OD unit, but even the factory figured this one out when they came up with the 518.

[flyinlow]

NO LOWER THAN my headers

My son wants to put a 518 in his '70 . That picture answers some of my concerns. On the '73-later you have to trim some of the ears off the sides off the tail shaft because of the separate T bar cross member those year cars have.
I made a mock up out of plywood on the output shaft of the 727 before I removed it and used it to check the 518 output shaft. The 518 is only 3.5 " longer, driveshaft angles were not changed much.

CDR: did you have to do much to the trans tunnel?

[cdr]

three small spots in front of the cross member i had to hammer out, console & carpet will cover it just fine. 

[flyinlow]

thanks