Hello all. I'm trying to find out information about replacing the rubber bushing in the chevy conversion engine mount. I bought the my Series I XJ already converted. I'm in the process of swapping engines (bbc to another bbc) and would like to replace the clapped out mounts while I'm at it. I have what seems to be an 80's John's Cars conversion, and from the little info I've found on this forum thus far it seems like a poor design, using a piece of a chopped off suspension arm welded to a plate. Someone mentioned in a thread that another member had found a replacement, but I couldn't locate any specific details.

I have another set of conversion mounts that utilize generic chevy mounts, but unfortunately they don't locate the engine in the same position, causing problems with header and transmission fitment.

So here I am, engine ready to go back in, and hoping to get some info about replacing those bushings, before dropping it in.

Thanks in advance

Pic of the old 454 coming out, rock hit pan while driving through canyons, pickup fell out of oil pump. lost oil pressure. added 4 extra quarts of oil, regained pressure, was able to putt it home and eventually to the Shop. Substitute motor going in while this one is worked over.

 

Some think John's design is poor, others not so much. I think Roger Mabry tracked down the rubber part's original application and a way to source them and then fit them back to the John part.


My car uses John's munts and so far, so good. Been there about 10 years!!


Oil is the enemy of all engine mounts. leaks get to them, eventually.


Or, As it is a John kit, he "may" sell you replacements. He is a tad touchy about that!!
Ok with selling replacements for kit users. selling parts of his kit, nope!


Or redesign the ones that use GM mounts and cut and weld to suit.

 

Well, Drat anyway! That's too bad!
I hope it all works out for you, you certainly have the shop space to do the work.
(';')

 

BBC worked over. That should be special...stop teasing, what cha' planning.


Just and Idea with out seeing what you've got....Get some 4 inch wide 1/4 inch thick steel plate. Bolt the plate to the chassis and weld the new BBC mounts to the plate. That will allow you the movement you need to locate the engine where it was. You can use a second plate and a spacer with longer through bolts to get the height correct if necessary.

 

Even though I replaced the rubber in the mounts.. (they were only a couple of years old at the time)... I would change them out for the Suncoast mounts.

Here are photos of the new rubber pieces from a Dodge Van...easily sourced. Very soft mounts and barely do the job intended... R&R them and then peen the edges over to hold them in place.

Having had Lumps with Suncoast, Mundorf and John's parts... the best choice is the Suncoast mounts and using the stock GM rubber pieces... especially with any engine with power as your big block...

Contact me if you need more information... we are close by... mabryroger@hotmail.com

 

I'm in the process of freshening up an older JC conversion and have the same issues with the engine mounts.What was the crossover I should look up to get the proper dodge mount?

 

Sorry, but I will not be back home until the 17th to check my records
for the motor mount specific model...


My "memory" says a Dodge Van, but.... they are crappy mounts to start
with and the original rubber is not great. The replacement rubber I used
is still working/looking great.


You are correct though, John mounts are farther forward compared to the
Suncoast mounts, had to cut off my driveshaft and adjust the trans mount.
But, the rearward change worked well as it made the balance better...

 

I do recall that Roger found the rubber in John's mounts to be sourdced from an older Dodge van.


I recall that when I prepped my LT1 for installation, the Johns mounts went forward a bit. the openings in the block existed.


And, when my helper and I got the LT1 in place, it took just a tad of urging to get the bolts to fit. We left the mount on the chassis just a tad loose, to get some "wiggle room". then with a long extension, those bolts were easily sent home.


I've no quarrel with Sun Coast stuff. Actually, the GM mounts they use are quite close to the old flat head ford stuff I am used to.


Smarter guys than I designed each of the three!!!


I am a tad curious as to the "suspension" origin of the Dodge/Johns system!!!


When I built my last "hot rod of the forties", I designed steel to bolt into the "A" frame to accept the Old Ford V8 mounts. I used channel iron. Open side down. Bolted in two planes. One used the same bolts to secure the shock absorber mounts.
Also served to stiffen the somewhat flexible Model A frame.


Lots of ways to do a job.


Carl

 

Were I to decide to do an SBC to Jaguar install from scratch, I think I could use both mounts! Jaguar chassis and SBC. Just design and fab a bridge between the two!!!


My son and I designed and fabbed a way to install A 429 CUI fords into his 40 Ford coupe using a similar technique.


Carl

 

Project is just coming off of the back burner from sitting with the engine apart for 2 years.Couple more days until you get back home are fine.I'm just starting to load the short block back together this weekend.

 

I paid $8.49 each in 2009, today they are even less (they know what they are worth!). Was at the bottom of the receipt box for this particular car...
I updated my Excel sheet with the part number for future reference.


According to the Napa chart they fit various Plymouths/Dodges...from 1963-1975.


The mounts are still working in the 1972 XJ that is almost finished --- only some upholstery work is left...hurray...yes I sold it but have stupidly
helped the new owner finish it up... it is actually going to the upholstery guy on Monday!

 

Picked up a set from the local napa store.Thanks for the info.