'68 318/727 vs 340/727 trans mounts

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HMBCUDA

HMBCUDA

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I didn't realize that 318's had a different trans mount than the 340's until i went shop'n for a replacement. My car was a 318ci, (now a 340ci), the original 727 trans. has been rebuilt.

I went with the 318 style energy suspension replacement, sure it will be fine, but.....

The 340 trans mounts seem to be a "spool" type with a different transmission cross member. (stronger design, no doubt)

My Question to "All" is if the transmission case, (cross member mounting area), was different?

In other words...would (if by chance I found a 340 trans mount/cross member), would it bolt right up to my 318/727 transmission?
 
Divenut said:
I think spoil mounts came around 73 ish.... maybe?
Click to expand...

Ok, was just wondering. could be a "rock auto" glitch...on their site, there are two different style Trans. mounts for a '68 Barracuda with a 727 auto. The 340's are a spool (looking) rubber mount, while the 318's are a square chunk with a single stud.
 
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HMBCUDA said:
Ok, was just wondering. could be a "rock auto" glitch...on their site, there are two different style Trans. mounts for a '68 Barracuda with a 727 auto. The 340's are a spool (looking) rubber mount, while the 318's are a square chunk with a single stud.
Click to expand...
Just went back to rock auto site to make sure "old timers" wasn't kick'n in again...Yes... '68 Heavy Duty Package auto. Trans mount is a "spool" type.
 
Marcohotrod said:
I think the 1968 spool mount was used in 318 727 in c body. spool mount in a body 1973
Click to expand...

OK, Thanks
But... talking '68 Barracuda 318/727 TF vs '68 340/727 TF combo.

If someone stumbles on this post and is working on their unmolested '68 340 barracuda with a 727 TF trans, (rebuilding the trans/changing the trans mount)
What type of trans mount is on your car?

If you would post pictures and/or a factory diagram of some sort. It would be interesting to see if the trans case, (mount area) is different.
It may save someone the head-ache of ordering the wrong trans mount, etc. (or not, Ha)

Thanks for your responses!
Dan
 
HMBCUDA said:
OK, Thanks
But... talking '68 Barracuda 318/727 TF vs '68 340/727 TF combo.

If someone stumbles on this post and is working on their unmolested '68 340 barracuda with a 727 TF trans, (rebuilding the trans/changing the trans mount)
What type of trans mount is on your car?

If you would post pictures and/or a factory diagram of some sort. It would be interesting to see if the trans case, (mount area) is different.
It may save someone the head-ache of ordering the wrong trans mount, etc. (or not, Ha)

Thanks for your responses!
Dan
Click to expand...

In 73 they went to spool mounts on A body, before that it is the square one. There is no difference in 340 or 318 trans mount or mounting area, they are the same.
 
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I did see rock auto and some other places listing the spool mount as an option too, like you did, makes things confusing for sure.
 
gtsdude said:
I did see rock auto and some other places listing the spool mount as an option too, like you did, makes things confusing for sure.
Click to expand...

Yes! (confusing) I punched in all the correct info. but put 340 as engine size,(what it is now), and the spool type mount came up. so got me thinking maybe the 340's were "engineered" stronger with the spool type mount. Thanks for letting me/us know what is correct!

Heard the poly mounts caused problems like trany cross member cracks and vibrations, but thought I'd take a chance on one of them. I feel all the rubber mounts are made outside of the US now a days and might be junk.
 
one suggestion from my stock eliminator racing friends - don't use a poly trans mount. If the engine has the torque to twist in place then the only give in the trans cross member is the rubber mount and the case it's attached to is cast aluminum...
 
In short, you need to use the type trans mount that coincides with the transmission cross member type you have.
 
All tranny mounts for the 67-72 A bodies is the square mount. 73-76 A body had the spool mount. U can use a 73-76 crossmember and mount in ur 67-72 A bodies. The bolts to secure the crissmember in ur car are 9/16. The 1970 up use 3/8 bolts. U just need to enlarge the bolt holes in the newer crissmember. Kim
 
SGBARRACUDA said:
In short, you need to use the type trans mount that coincides with the transmission cross member type you have.
Click to expand...

oldkimmer said:
All tranny mounts for the 67-72 A bodies is the square mount. 73-76 A body had the spool mount. U can use a 73-76 crossmember and mount in ur 67-72 A bodies. The bolts to secure the crissmember in ur car are 9/16. The 1970 up use 3/8 bolts. U just need to enlarge the bolt holes in the newer crissmember. Kim
Click to expand...

Thanks Guys, I should be good with the square poly mount, i broke down and bought/installed Poly-Lock (biscuit) motor mounts this...last year, it's solid as a rock, and my engine probably doesn't have a heck if a lot more torque, than what came out of the factory, so should't twist enough to damage the trans case, etc. kind of what i was thinking too.

For others out there though...Good to hear that the cross members are fairly interchangeable with a bit of (simple), modification. I was reading somewhere, (on the web), that the '73 -'76 transmissions are better to rebuild, and install,(if you're not doing a full on pre-'73 restoration), because the bearing area in the transmission was, (improved), larger surface area.

It doesn't really matter I guess, but still curious about the trans case itself...that is...are the '73-'76 trans case "cast" slightly different (at the trans cross member area), to work with the "new and improved" '73-'76 spool mount trans mounts/cross member.
OR
did the transmission cases stay the same,(cast identical in the mount area),'68-'76?, and ONLY the transmission cross member/mount design change in the '73-'76 A body?

(Dam! think My cat just died),
Happy New Year To ALL!
Dan
 
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