1961 Ford Thunderbird Engine Frame Issue

I acquired a '61 Thunderbird in the past year and it’s engine had been replaced with an 80’s 5.0 HO from a GT Mustang. The original 390 is still in great condition, it just needed it’s valve seals replaced and the old owner wanted another engine in there in the meantime. Unfortunately, the Thunderbird only ever had a wide-block engine which means there was never a need for Ford to make it a bolt-on bracket but rather a simple weld. The owner before me cut the frame to make the new brackets fit a small-block engine rather than the big-block. The issue is that none of my local shops are willing to attempt to do the weld job to get the frame where it needs to be without the dimensions needed for said frame. I was wondering if the dimensions were recorded somewhere so that I can get the engine put back in? I bought an OEM shop manual for it and no dice. I really don’t want to have to restomod the car when I have a perfectly good original 390 ready to be put in.

fyi: I know a bit about this kind of thing but not a whole lot. My mechanic who used to work for Mercury in the 70’s filled in the blanks for me. If I’m off in someway, I apologize.

Just to clarify, the previous owner cut the frame? Or just the motor mounts which are welded to the frame?

Sounds like what you are looking for is how the motor mounts should be set up. Is that correct?

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I looked some stuff up, take it with a grain of salt:

-61 to 63 Thunderbirds were common platform using a “dual-unitized” structure that connected at the cowl. This was very similar in dimension to the Lincolns of the same era. So if you can’t find a local Thunderbird to look at maybe a Lincoln gets you close?

-look into vintage thunderbird club international? [a club is more likely to have someone with this kind of information or a stripped frame sitting there to go measure]

-local welders are unwilling without the dimensions… or they just don’t want the job? Where I live welding frames is now a big no-no. Most mechanics won’t safety a frame with obvious mods/repairs. Now, if you know what you are doing this isn’t really an issue, but thank the truck frame notch hackers this gets looked at.

-You may have to buy a parts car. In the end this could be good for more than just dimensions. If your frame is really hacked up you might need a donor clip (having trouble picturing what they could have done to you frame just for motor mounts). If you don’t have to destroy the donor car you can always move it along once your parts needs are pulled off it.

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They cut the frame itself. Pretty much unable to put the brackets on to put the mounts back on for the 390 in the correct spot.

I mean how easy would it be for someone else with the same style T-Bird to get the dimensions for the frame for the brackets?

Relatively easy. Especially if they have the engine out and front clip off.

That’s why I suggested the T-bird club. More likely to get a fast response from someone that can do this for you.

It’s possible some of the vintage auto wreckers (i.e., Flatla Auto in Alberta, Canada) would have one sitting around. A parts yard would probably rather sell you a front frame clip than go measure it, but many in the hobby are helpful above all else.

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I’m not a Ford guy, but you have obviously many more issues than “frame mounts”. The 302” is a small block Windsor, the original 390” is a FE series. Absolutely nothing will interchange between the two. Transmission bolt patterns, all of the accessories mounts and the exhaust hookups from the manifolds back. Before you even begin, take a hard look at that “original motor”, you need everything that bolts to it for this swap to work.

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