429 Engine swap

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bigpoppachief07

New member
Joined
Jan 25, 2013
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Location
North Carolina
My Car
73 Mustang Mach 1 w/302
73 Stang.JPGHello everyone.

I'm new to the forum, but I've found my home for me and my 73 Mach 1!

Here's the deal: I've got a 429 ready for rebuild and I'm gonna swap it out for the 302 that's in the stang.

Can anyone direct me to someone who has done a 429 swap into a 73 Mach 1?

I've read everything I can on doing it and I have just about every Mustang mag there is, but I'm still not sure on what this will all entail.

If anyone can help me out, I'd appreciate it.

Thanks,

Jeff

 
Let me say I have never done that swap but assuming you are staying with a similar tranny (C4 to C6) or the same 4 speed, assuming you have all the correct accessory brackets for the belts and the right pulleys and hoses, the only thing that jumps out to me are motor mounts and hooking up the exhaust to whatever you have. I'm sure other will chime in as to what else to consider. Aside from power you may notice the handling will not be for the better due to the heavier engine. :(

With all the new power you should consider the rear spoiler flip too.

 
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Hello everyone.

I'm new to the forum, but I've found my home for me and my 73 Mach 1!

Here's the deal: I've got a 429 ready for rebuild and I'm gonna swap it out for the 302 that's in the stang.

Can anyone direct me to someone who has done a 429 swap into a 73 Mach 1?

I've read everything I can on doing it and I have just about every Mustang mag there is, but I'm still not sure on what this will all entail.

If anyone can help me out, I'd appreciate it.

Thanks,

Jeff
::welcome:: ,be sure to post in the introductions, if you havn 't already.All I can say is I bought a 351 car last year that had a 460 put in,the guy did some stuff right & wrong.What I"ve learned is ..you need big block coil springs,you need a trans. to back up the H.P. (mine is C6) don't use Crites long tube headers(they hang too low)mine have dents to prove it) engine mounts for big block(crites in mine)I don't know if the radiator for 302 is same as 351,but mine seems to cool ok. A 9 inch rearend is good for all that torq as well.Save lots of money for gas & tires .:p
 
Welcome to the club, Jeff. As mentioned, I would post this thread in the Introductions area. It gets alot more traffic and more chances of finding someone who has done the swap.

Good luck - glad to have you here!

 
...what Kermit460 said:)!

I would add that as you begin to acquire the additional parts, you would do well to tell "parts" folks that you have a 1971 with 429CJ motor. Many parts such as mounts and stuff are readily available from the local "parts", i.e. Autozone, Napa, etc., if you utilize the 1971 mustang approach.

There are several Members on the Site who have or are putting 429/460 motors in their 1971 - 1973 Mustangs so you should be able to obtain answers to any specific questions that you may have as it relates to the install.

BT

 
There is a site dedicated to the factory 429 cars that has a ton of pics and part numbers that may be some help when you need oem part numbers....i just search for 429 supersite. Its not a forum community site, just lots of pics and part numbers. Btw, the 429 cars are rare and collectble and very cool. But imo the clevelands are better for our cars because they are lighter, which is important if you plan to drive a lot on the street. And they are just as rare in the muscle car world! And they can produce tons of power and sound great. Just a thought... But for straight line times and sheer brute torque the big brother to the 351c is an impressive engine for sure.

 
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I am going to do the same to mine and there are plenty of big block cars on this forum so information should be easily obtained. BTW welcome to the forum from Arkansas

 
Beautiful car by the way & welcome from Fayetteville, NC. I can't tell you much about the 302 to 429 swap but I did an I6 to 289 swap and ran into a few issues...not insurmountable though. I think you'll probably need...at a minimum...

1). Frame to engine mounts..not just engine mounts

2). Possibly new radiator (depending on the in/out hoses) & capacity

3). Different trans. I doubt the C4 can handle the 429. With that being said, if you are going to marry up a trans make sure your flexplate/flywheel are correct. New trans = new trans cooler lines & vac line to modulator

4). You may need different front springs to handle the weight

5). Work through marrying up the exhaust with what you have

6). May need a new accelerator cable depending on length

7). Probably need some rubber gas line handy since you fuel pump is probably in a different location

8). Heater core lines should probably reach

9). Double check vac lines & tree to ensure you have enough inlets on the tree

-KR

 
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I was able to reuse my frame to isolator mount and bought the isolators and block to isolator brackets from mustangs unlimited look under 71 429 parts and I am going with an auto to 6 speed manual conversion still need the flywheel, clutch, pressure plate, bell housing, ect, ect, ect. It feels like a lot but she should be seeing the road in october if I don't hit any huge snags.

 
I went from a 351c to 429 and all I had to really changed was the motor mounts , new bellhousing ,flywheel ,front coil springs and hooker headers(the only header available at the time and they do go under the front crossmember and hang down a bit). As far as parts like staters, water pumps ,ect do like Cobra3073 said and tell the parts house you have a 71 429 and you should be ok. Hope this helps some welcome to the site.

 
A few tips and observations - I did this swap on a 351C car a few years ago

1. Summit sells a perfect fit AL radiator for this setup, part number SUM-380463. I have had zero overheating issues.

2. I am using the hooker supercomp headers, 6115 I think (not the ones that you have to cut hole for). They scraped constantly until I put some new KYB shocks on the car, even just going over a pavement transition or sudden dip. The new shocks eliminated most of that. I think if I had it to do over I would go with the FPA mid-length headers.

3. I am running a 3" exhaust with cutouts, that does not help overall ground clearance. I would go with 2.5" with cutouts (I pick up about .3 on the dragstrip w/ uncorked exhaust.

4. Find a junked late 60s-Early 70s BBF and get ALL the brackets, pullies, etc., not just the ones you think you will need.

5. If your car is an auto, one good-to-know thing and relief to me was that the 351C C-6 shifter/linkage worked and lined up perfectly with the BBF-C6. I have a '69 that was originally a 351W-FMX and it was a nightmare trying to get the shifter to work well with a 351C-C6 I ran in it for a while (TKO now).

Anyway, just wanted to give a little input from this board noob.

 
A few tips and observations - I did this swap on a 351C car a few years ago

1. Summit sells a perfect fit AL radiator for this setup, part number SUM-380463. I have had zero overheating issues.

2. I am using the hooker supercomp headers, 6115 I think (not the ones that you have to cut hole for). They scraped constantly until I put some new KYB shocks on the car, even just going over a pavement transition or sudden dip. The new shocks eliminated most of that. I think if I had it to do over I would go with the FPA mid-length headers.

3. I am running a 3" exhaust with cutouts, that does not help overall ground clearance. I would go with 2.5" with cutouts (I pick up about .3 on the dragstrip w/ uncorked exhaust.

4. Find a junked late 60s-Early 70s BBF and get ALL the brackets, pullies, etc., not just the ones you think you will need.

5. If your car is an auto, one good-to-know thing and relief to me was that the 351C C-6 shifter/linkage worked and lined up perfectly with the BBF-C6. I have a '69 that was originally a 351W-FMX and it was a nightmare trying to get the shifter to work well with a 351C-C6 I ran in it for a while (TKO now).

Anyway, just wanted to give a little input from this board noob.
GREAT post and welcome to the club. This info is much appreciated - please post a short intro in the Introductions thread so we can give you a proper welcome. Glad to have you here!! ::welcome::

 
thanks to everyone who replied to my post.

I just posted in the Introductions form as well (you know how us noobs can be - LOL).

I'll keep everyone up to date as soon as the money starts flowin again! LOL.


Another question for everyone -

The 429 I'm transplanting into the Stang came with an AMX auto trans (71 Torino). I want to use it, but I see a lot of people that have 429's use C6 trannies. I'm gonna stay with an auto, I DO NOT like manual trannnies, so please no posts trying to twist my arm (LOL).

And you can trust that I've been all over the 429mustangcougar site to get all the info I can.

Anyone got any ideas or experiences?

 
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bigpoppachief07,

I just finished a swap similar to yours. I went from a 351C C6 to a 460 with top loader 4 spd. Your experience should be typical. I would suggest that you decide first what your exhaust is going to be either headers or stock type manifolds because what engine mounting set-up you choose, will effect height of engine. I choose a OEM 1971 Mustang 429 type set-up which will work with all exhaust, but can be costly to gather all parts, especially the frame mounts. Most items are available from our very knowledgeable & reputable suppliers listed on this site.

I would suggest using a C6, due to its dependability & availability. Search this site there have been many discussions on this topic.

If you have additional questions, there is a wealth of knowledge here on this site, Welcome !!!

Thanks, Jay

::welcome::

 
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The 429 I'm transplanting into the Stang came with an AMX auto trans (71 Torino).
Do you mean FMX? I have never heard of a 429/FMX combo from the factory.

I ran a small block FMX behind my 460 for several years using a bellhousing from a 351M/400 FMX which has the big block pattern and it worked fine. Perhaps that is what was done with the 71 Torino.

 
anyone ever mention yer spoiler is on backwards?
Yeah, but I'm dyslexic. Instructions are not my forte! LOL

The spoiler attached this ways makes the drag coefficiencie better. LOL



The 429 I'm transplanting into the Stang came with an AMX auto trans (71 Torino).
Do you mean FMX? I have never heard of a 429/FMX combo from the factory.

I ran a small block FMX behind my 460 for several years using a bellhousing from a 351M/400 FMX which has the big block pattern and it worked fine. Perhaps that is what was done with the 71 Torino.
Typo. I did mean FMX.

 
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Yeah, but I'm dyslexic. Instructions are not my forte! LOL

The spoiler attached this ways makes the drag coefficiencie better. LOL

LOL yeah until it splits apart....

 
I am doing the same swap in the near future. I have the engine, need full motor mounts, c6 transmission with crossmember, c6 driveshaft, 9 inch rear end, gonna go with an aluminum 3 core radiator, 429 springs, and headers. these are all things i need to acquire…and for as cheap as possible cuz the wife is not too happy about this swap, since my 302/c4 combo runs great.

 
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