[Jack Gifford]

Straycat- do you realize that the Hurst mount attaches also to the bottom of the timing cover, using a '55-'58 front mount bracket? If you move the Hurst mount ahead the thickness of a timing cover stud nut, the bottom mount bracket holes won't align. I really think the original design idea is best- keeping the mount up as close as possible to the timing cover.
Depending on the stiffness of the rubber in your "trans mid-mounts", you should be okay. How much torque do you estimate to the driveshaft in first gear (max. engine torque x first gear ratio x torque converter mechanical advantage)? I estimate that I had about 1,700lb.ft. in my '57 Chevy (415 engine torque x 4.08 first gear, no torque converter) and it was fine with the Hurst and original '58 Pontiac bellhousing mounts, which were fairly soft.

[straycat]

bill, yeah i see the mount still shown on speedways website but no longer a price. how about a little website update speedway. i had a spotts motor plate it could be made to work but just not the retro look i wanted.. ..pontiac jack i'm not planning on using any rubber for my fabricated trans sidemounts. i'm going to fabricate a piece of 1/8 or 1/4 metal following the contour of the t 400 trans lower 2 trans to motor bolts then extend to the frame and bolt to an an angle iron on both sides. the angle welded to the frame. this and a solid trans mount should stop the torque flex. i'm going with the grade 8 bolts for the motor mount. i have a set of Jardine headers that with some minor tube relocation should work. i will have to grind a little off the steering box and the outer header flange to give plenty of clearance. the motor is a 455 w/1971 #96 heads, o68 cam and 1.65 rockers, 66 tri power, stock converter, t 400, 57 rear w/4:10 gears on 31 spline spool. thanks to everyones interest in these projects. bob

[uforacing]

I like this thread! I still remember an old HotRod? issue where they took a 59 Corvette and dropped in a 389. I remember they had to add something like 400 Lbs of sand bags to the trunk!

[Jack Gifford]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by straycat:
... and a solid trans mount should stop the torque flex.

...57 rear w/4:10 gears on 31 spline spool. </div></BLOCKQUOTE>

I guess you're willing to put up with the harshness/noise/vibration compromises of solid mounts? To me, solid mounts are like setting automotive design back seventy years, as far as interior comfort; but to each his own!

Just curious- what '57 rear? Chevy?

Thanks

[Jack Gifford]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by straycat:
i'm also going to install a turbo trans midmount available from 55-57 parts dealers that will go to the frame. </div></BLOCKQUOTE>
Again, I'm just curious- did you find that such a mid-mount was not available? You talked about fabricating one, in your later post.

[PLAY400]

I thought read somewhere here before, maybe the race section, that you may getby mounting the motor solid but you should leave the trans flex unless your putting a midplate in. And alot of chebby guys are moving away from the factory front mount and going to side mounts because of flex. Tooo much power in these motors today

[straycat]

pontiac jack, the 57 rear is a pontiac. car is for strip. not done anything about trans to frame. i just think it will have too much torque movement with the hurst motor mount with the rubber insulators and could rip apart. maybe just a good steel turnbuckle fastened to the block.

[Jack Gifford]

For race only, I think solid mid-mounts are a great idea. Sorry, I had it in my mind that you wanted to make a stoplight-presence with your Pontiac-powered Chev!

[Poncho Catalina]

Hi
I’m looking to install a455 /400 trans in a 56.Pontiac. I have a hurst mount, like the one in the post “Pontiac in a 5 6 7 Chevy. What I need to know is if it is the right one for the late motor? What is the difference between the late and earlier mount. Can the two be interchanged, and why? I do not have anything else to go with it. Could anyone send me a copy of the instructions? What do the mounts for the frame look like?
Thanks for the help
Poncho Catalina

[Jack Gifford]

Catalina- Please see page 2 of this topic regarding early/late Hurst mounts. But I don't know that a Hurst mount would be of much value in Pontiac-into-Pontiac, as the whole idea was to adapt the Pontiac engine into other cars. Member Bill Eveland can fill you in on later engine into '55 Pontiac.

[Poncho Catalina]

It would still be of help pontiac in a pontiac, because the late motors have mounts on the side and the 55/56 body mounts the motor in the front by the timing cover.
Thanks for you time and input
Poncho

[Jack Gifford]

Saw something very interesting in the July 1971 issue of Hot Rod Magazine. In a rundown of aftermarket exhaust companies, Tubular Automotive was listed as offering headers for Pontiac V8 into '55-57 Chevy. I'm not familiar with the company, and don't know if it's still in business or not. But if someone could get really lucky and score a set of those headers at a swap meet or such......

Edit: A web search turned up an address & phone#, but they may be old:

Tubular Automotive
P.O.Box 279
248 Weymouth St.
Rockland, MA 02370
617-878-9875

[Bill Eveland]

I think using the side mounts would still be a better deal. Without some kind of center support/midplate and only using a front plate and rear trans mount, you would be putting alot more stress on the trans tailshaft . The early Hydramatic along with the front mount off the timing cover had rear side mounts on the trans bellhousing, not like a single mount on a TH 400. I wouldn't be suprised if the Th 400 tailshaft would crack or break. If you still had your Hydramatic crossmember, i'm sure you could fabricate some mounts to go to the trans bolt holes for support.
For my Th-400 rear mount I used 1/2" steel plate and made a mount that sits on top of the bottom edge of the x-frame. I can post a pic if your interested. Bill

Originally Posted by Poncho Catalina

It would still be of help pontiac in a pontiac, because the late motors have mounts on the side and the 55/56 body mounts the motor in the front by the timing cover.
Thanks for you time and input
Poncho