318 to 440 upgrade- What about the Drive Shaft

[68Chargerguy]

Hey Guys, I just found this site yesterday and it is great! I'm Changing out a 318 for a 440 on my 68' and just wondering if I'll have to change the Drive shaft and rearend also? Any help woul be appreciated.

[green69rt]

There's more to it than juist the drive shaft.  Yes I think the drive shaft is different.  The length is diffenent.  Other differences,  torsion bars, K member, radiator, tansmission bolt pattern.  Mayby more stuff. 

[skip68]

   WELL WORTH IT THOUGH !       Welcome to the site.       We need some pictures.   

[terrible one]

With a 440/727 and 8.75 rear the driveshaft is 52.07" center to center

[68Chargerguy]

How can you tell which rearend you have? When I looked at mine this morning I didn't see any numbers. Is there a code some where on the rearend that I'm missing?

[WingCharger]

[68Chargerguy]

Thanks WingCharger, mine is definitely an 8 3/4.

[WingCharger]

Good! A lot of guys will only mess with the 8-3/4. Lots of aftermarket availability.

[69bronzeT5]

Don't want to steal your thread but....my '69 was a 318...now has a 383. Will the original K-member still work?

[FLG]

Yes bronzie...k member differences are only on 3rd gens between big and small blocks...think it was only 73-74 cars.

[Foreman72]

Yes bronzie...k member differences are only on 3rd gens between big and small blocks...think it was only 73-74 cars.

exactly right...but motor mounts will be different...i feel like someone has a SB to BB conversion kit...summit maybe...no paddock...thats the one...the kit has everything you need to mount the sucker...

gotta say chargerguy...no love for the 318 huh 

[Chatt69chgr]

Std torsion bars are 0.92 inch for BB.  Some prefer to move up to the 0.96 however.  Rear Springs are different along with U-bolts.  Radiator will be different.  On my 69 with 318, the fan blade was the same as used on 69 440-speed.  Will have to get different fan clutch.  There is a Hayden piece that everyone uses.  Don't recall the number (maybe 2764 or something) that fits a Jaguar.   Obviously, the exhaust system.  Also, don't know what your 440 came out of but you will need the HP exhaust manifolds if going stock.  Available from Year One.  And your braking system should be upgraded since you will want to be able to get out of trouble faster than you can get into it.  Need disc's on front preferably.  Some like booster.  Some don't.  If you go disc's you will need 15 inch wheels to clear the calipers.

[68Chargerguy]

 I'm not sure what my 73' 440 motor came out of but it did come with the exhaust manifolds. Is there something special about the exhaust manifolds to make it work in my 68' charger or were you referring to the difference between 318 and 440 exhaust manifolds? To me the 440 manifolds looked exactly like the ones on a 383 that I pulled out of a 66' monaco last summer.

[Chatt69chgr]

I don't know if the 73 manifolds will work or not.  The ones I was referring to were these:

http://www.yearone.com/serverfiles/fbshopmain2.asp?input=manifolds&SM=1&SC=1

YO says that they fit 68 and 69 383 & 440. 

[68Chargerguy]

Thanks, I'll keep those in mind if for some reason mine will not work.

[yammie]

I'm replacing the shaft seal in my 8 3/4" rear end but want to have the seal in hand before I disconnect the drive shaft. NAPA has 2 listings for the seal, one for a 1 3/4" shaft and one for 1 3/8" shaft. I've got a 68 r/t 440 with 727 trans. Is there a way to confirm the correct size without disassembling first?

tks

Paul

[mopar0166]

where do you get a driveshaft from?