460 Swap Mounts: Size Does Matter!!!

Hi y'all,
I learned a hard lesson this week and want to share it here to help prevent someone from dealing with the same thing. I used the extreme duty 460 swap motor mounts https://shop.broncograveyard.com/460-Mts-302-351W-1980-96/productinfo/30907A/ in my 84 Bronco and discovered, only after making it much further along in the engine bay, that they make the engine block sit at least an inch and a half higher than it "should".

I didn't have a standard for comparison so it didn't seem to be sitting too high to me. It wasn't until I installed the evaporator box that I ran into interference from the headers. JBG tech did acknowledge that the L & L version is about 1/2" thinner (but that one is rubber). I ended up buying the Trans-Dapt model 4226 poly mount and, once installed it dropped my engine to where I would expect it to be. I measured it and noticed that it is about 1/2" thinner between the mating surfaces and the stud is about 1/2" higher up on the mount. I can't confirm that these measure the same as the L & L.

Be aware, if you use the JBG extreme duty 460 swap mounts, your engine will sit higher!

Good feedback. I was previously looking into those, but managed to find a 460 parts truck and I robbed the perches from it so I could run stock 460 mounts. I think header fitment is an issue even on stock 460 trucks, so every little millimeter you can save is good.

Yes, that certainly is good information.  And yes, header fitment IS a problem on 460-equipped trucks.  That's why I had to trim Big Blue's frame slightly to get the L&L's to fit.

FYI I am using Mad Dog Headers #9229. They are fenderwell exit. They fit great except for the aftermarket Duff damper mounts. My buddy is a wizard with a grinder and did this amazing job:

Now do some of you understand why I am never putting headers on Darth. My first run-in with headers was on my 1964 Falcon with a 260 V8, the left side was an amazing bundle of snakes at 1.5" primaries. 7 & 8 went down, turned out under the frame and then back in to the collector, 5 & 6 ran reasonably straight down and back to the collector. the right side was cramped, but I don't remember any strange contortions on that side. These were Hedman I believe as they were the only Falcon/Comet ones available.

The Shelby wasn't bad, left side you still had to remove the clutch cross shaft, right side, pull the plug wires and for safety, the plugs and the header would come out from the top, either the original Shelby-American Tri-Y or the Hookers I replaced them with.

Yep, looks like I just found the same issue, didn't seem like it wanted to sit down in the perches with them.....  add another $167

Way better, thanks for posting!!

Anyone needs the Bronco Garage ones let me know.

Glad I could help after the fact but sorry you had to learn the hard way too. JBG needs to put an advisement on the listing for those HD mounts that they cause the engine to sit higher than stock. No way anyone could tell that just by looking at the pictures online.

You have to keep in mind, Ford never intended to put the 460 in the 1980 up trucks. It was only after being killed in the heavy towing market by GM with the 454 availability that they realized their mistake. Dodge was also sort of stuck, biggest engine was a 360.

If Ford had done something with the 400 the 460 might not have been needed. I sent Gary some pictures of Darth's engine compartment before he bought Big Blue, his first comment was "How high did they have to drop that from to get it in?". The factory mounts on a 460 are actually so low on the engine that they block access to the center pan bolts. The front crossmember is also 460 peculiar, with an access hole for the oil filter adapter bolt (the filter is turned forward and down to clear the power steering pump and allow it to be reached from below).

One item to be aware of, on the stock exhaust manifolds, the left side motor mount has a heat shield to prevent the heat from melting the rubber.

Your point is valid, but they're also marketed as motor mounts for a 460 swap.
When I tried to install the engine, the bolts barley dropped into the perches and the mounts never contacted properly.  The other ones dropped right in like they were advertised to do.