460 swap on a 72 Mustang base

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ashwis

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Apr 13, 2024
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Location
austin
My Car
1972 mustang base with 302
I currently have a 1972 mustang with the 302 that id like to do some modifications to but trying to decide what avenue to go, I have a 1985 f250 with the 460 big block that I will be doing a engine replacement on in the near future however Ive been debating using the old engine and having it rebuilt to put in my mustang. Im wondering if anyone has ever done this swap before if itll fit inside with factory mounting locations or if itll become a custom fabrication job and if it is possible what would be a good transmission to go with it?
 
The 71-73 were designed especially to accept the 429. Engine wise you only need 385 series engine mounts similar to 429. For the trans, I don't know what you have but you can have a pretty big bell housing as it was the case for the C6/429 combo without any firewall/tunnel issues. Drive shaft length depends again on your trans (and governor type/length if automatic). And you will have to find a set of headers that fits.
Good luck!
 
Roy built a pair of block brackets for me this past winter, though I had located a pair of the 429/71-72 Convertible frame mounts. The block brackets are the hardest part to find IMO. Immaculate work and very nice. He even milled a "R" and "L" into them. First class guy. Highly recommended!
 
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Roy built a pair of block brackets for me this past winter, though I had located a pair of the 429/71-72 Convertible frame mounts. The block brackets are the hardest part to find IMO. Immaculate work and very nice. He even milled a "R" and "L" into them. First class guy. Highly recommended!
Do you have a picture of the brackets and mounts you ended up using?
I'm trying to do the same thing that you've already done by the looks of it!
 
I can give you pics of mine. The man you want to talk to is Roy as listed above. Here's what he made for me.
 

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Thanks! Those are some stout looking brackets. Do you (or anyone else here) have the dimensions? I'll make myself a set if I can get measurements.
 
Roy didn't charge a great deal and he has jigs made up to use any frame brackets you have, even the '73s. 71-72 both are the same, but the '73 are unique since Ford went to the retention style motor mounts due to federal regulations. Give Roy a call. He's a nice guy and you'll likely be surprised at the quote he'll give you. He starts with a C4 channel and welds ears on to attach to the motor mounts. They're heavy, but you'll likely never break them, even in drag racing applications. I know a few members are running his brackets.
 
You can also buy the engine mounts as a set online. They are listed under 429-460 conversion kit.not sure on the price.
 
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You all work entirely too hard. A 460 in a 71-73 is a bolt in, it was designed for it.

For motor mounts, use the stock idolators that bolt to the block.

Then swap the brackets that bolt to the frame side-to-side, and elongate a couple holes.

For more see my post here.
https://7173mustangs.com/threads/351c-to-460-swap-opinions.44673/#post-450164
Which isolator style are we talking? I've got a van-type with no rubber, the superduty style and then there look to be around 3 or 4 other styles over the years.
 
You all work entirely too hard. A 460 in a 71-73 is a bolt in, it was designed for it.

For motor mounts, use the stock idolators that bolt to the block.

Then swap the brackets that bolt to the frame side-to-side, and elongate a couple holes.

For more see my post here.
https://7173mustangs.com/threads/351c-to-460-swap-opinions.44673/#post-450164
I'm running Hooker SC headers. The engine needs to sit at the factory height to clear the frame and suspension, plus fan height to fit a factory fan shroud.
 
Which isolator style are we talking? I've got a van-type with no rubber, the superduty style and then there look to be around 3 or 4 other styles over the years.
I am on the road right now heading from SoCal to Hot Rod Power Tour, KY. I cannot provide pictures for about a month

I put a 71 T Bird 460 in a 71 Mach 1, and a 76 T Bird in a 73 Mach 1. My 84 E350 came with a 460. So I have those as references.

The 73 Mach 1 I did in 1998, so memory is a little fuzzy.

Imagine you pulled a 351 from a Mustang. There is an isolator bolted to the engine. They mate with brackets bolted to the frame. I reused the frame brackets, just reoriented them. The only difference in mounting is that the 460 is wider, and the brackets are angled so they change width by turning them around. I then used the 460 isolator that matches the 351 frame brackets. It is a common part.
 
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Roy built a pair of block brackets for me this past winter, though I had located a pair of the 429/71-72 Convertible frame mounts. The block brackets are the hardest part to find IMO. Immaculate work and very nice. He even milled a "R" and "L" into them. First class guy. Highly recommended!
Thanks for the lead, Roy is making me a set of engine brackets now. Where did you get your rubber engine mounts from?
 
This is a 71 M1. The last engine in there was a 460. It was my wife's daily driver. It is identical to her current 73 M1.

Those brackets on the frame, are the ones that previously supported a 351C. The 351 and 460 mount systems are the same. They both use the same design frame-to-block mount - 351 and 460 just have different bolt patterns on the block. And, the 460 is wider. There is a single design for the frame brackets. Mount them one way. and they are the width for a 351. Mount them another way and they are the width for a 460.

These are 351 brackets in that one of the four mount holes is offset so that is impossible to mount them other than correct. To use them for a 460, install three bolts, then drill the remaining overlapping hole to accept a bolt.

The 460 bracket-to-block insulator is the same design as the 351, just a different block bolt pattern. It is a common part. See att pic.
 

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The factory actually made 3 different Frame mounts for the 71-73 engines. There was a standard small block bracket for coupes and fastbacks, a small block convertible and 429 engine version, and the 1973 3-piece design that was mandated by the government.

If you want to run off-the-shelf headers like the Hooker SC's on the the car, you need to get the engine at the correct height, as the front two cylinder primaries pass under the front suspension. In the attached pic see the three different versions of frame mounts. The standard small block coupe/fastback brackets are on the left, the convertible/429 brackets are in the center, and the '73 type are on the left.

If you're running exhaust manifolds, perhaps the standard mounts can be made workable. But headers really need the correct convertible frame mounts. Roy can fab up block brackets for you to use the small block coupe/fastback brackets frame brackets.
 

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The factory actually made 3 different Frame mounts for the 71-73 engines. There was a standard small block bracket for coupes and fastbacks, a small block convertible and 429 engine version, and the 1973 3-piece design that was mandated by the government.

If you want to run off-the-shelf headers like the Hooker SC's on the the car, you need to get the engine at the correct height, as the front two cylinder primaries pass under the front suspension. In the attached pic see the three different versions of frame mounts. The standard small block coupe/fastback brackets are on the left, the convertible/429 brackets are in the center, and the '73 type are on the left.

If you're running exhaust manifolds, perhaps the standard mounts can be made workable. But headers really need the correct convertible frame mounts. Roy can fab up block brackets for you to use the small block coupe/fastback brackets frame brackets.
What is your point? I said you can put a 460 where a 351 was in a 71-73, and use the existing frame brackets and stock insulators. I have done it twice. What exactly is the argument?

The brackets you see in the 71 came with the 351. The brackets in the current 73, came with the 351. Seem to be the same.

As for "off-the-shelf headers", I always expect to need to rebuild them.
 
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The isolators for the O.E. 1971 Mustang only 429/460 engine mounts (the style that have a bracket that bolts to the engine with two studs, then the isolator and unique 429/460 frame stands) are available from Don @ OMS:

https://www.ohiomustang.com/store/order_page.asp?itemid=2559

These isolators are common with 67-70 Mustang/ Cougar FE engine isolators. Sometimes searching for this application not 71 Mustang/ Cougar 429 yeilds better results.
 

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