What year Mustang?

 

1967 coup

 

I have done a lot of research and even asking around on here for just about the same question. If the car is an automatic and has a C4 you will need a bigger C6 because one is for a small block (289) while the other is for a big block (390). A shock tower reinforcement kit will be recommended with a monte carlo bar and stiffer springs. If you were to go all out a stroke it to a 428, that new transmission i was talking about earlier will have to handle 500+ hp and a lot of torque. You might think about an upgrade in the rear end also if it is a stock rear.

As far as making it a 428 it would just require a stroke. You could squeeze out 427 cubic inches out of a 351 with no bore, a 390 will easily do it too.

 

What about motor mounts. Do I just buy 390 ones and they go in place of 289?

Would a ford 9 be fine if I'm just making it a 428. No performance added.

 

Yes the mounts fit right in. Thats one really good thing about having a 67. Im guessing you are talking about a 9in rear and that will work just fine.

 

Get Yourself a Shoehorn

I have an FE in my 67 fastback which makes it a busy engine bay.

If you need additional help, the Ford FE forum is also a great source of information if you plan on dumping a big block in your Mustang. Its provided me with a lot of information over the years.

332-428 Ford FE Engine Forum

There's a little but more to it than dropping an engine in; like a larger radiator etc... Not saying there aren't folks on this forum who can tell you everything you need to know. But, the FE forum can also help you along the way. There are many folks here who are joint members so you'll have plenty of help.

Good luck!

 

There are a lot of little things that have to be changed besides the transmission, motor mounts, exhaust, driveshaft, larger radiator that will be required for the 390. I went from a 302 to a 351C in a previous Mustang and it was a headache with all the changes I had to do. That's staying with a small block.

 

I have the 3 speed standard trans. 3.03 I believe? Just need to switch bellhousing at that point or is it too much power for that trans?

 

Well.. you "can" make a 428 out of a 390, but generally not done. 428's had a 4.130 inch bore and the 390 has a 4.050 bore, taking a 390 block to 0.080 over is getting way on the edge... IIRC 428 crank in a stock bore 390 yields a 410.

And "run of the mill" 66-67 428 vs CJ or SCJ are another difference. PI's and other early P, Q, O code 428s used in Galaxies and Mercury's ("7 liter") were also "428s". So depends if you just want displacement, or the whole assembly to be a correct "428" (PI vs CJ vs SCJ)

For a 390 block, just drop a stoker kit in it, add 428 heads/intake/manifolds and to all the world except a few it will look like a 428 and perform better... common 390 stroker is a 445.

As noted swapping 289 to 390 takes a bit more than "the engine".

A stock 3 speed 3.03 might struggle keeping up with a moderately powered FE and some "spirited" driving.

Some info here:

https://www.428cobrajet.org/id-block

428 Engine Specifications | Classic Cars

428 CJ -- The Ford V-8 Engine Workshop

 

I'm pulling the engine and trans out of a ford country sedan. Can I use the radiator that came in the sedan or do they make a larger radiator that fits in a mustang core support


As far as weather to make it a 428 or leave it a 390. Is there much to gain or is the gain already enough from the 289 to a 390?

 

I'm pulling the engine and trans out of a ford country sedan. Can I use the radiator that came in the sedan or do they make a larger radiator that fits in a mustang core support

As far as weather to make it a 428 or leave it a 390. Is there much to gain or is the gain already enough from the 289 to a 390?

You'll have an exhaust problem with the heads, Mustang exhaust manifolds cannot be installed due to lack of the bolt flanges to attach them. You'll have to use aftermarket headers with a dual pattern.

It's almost certain that the big car radiator cannot be used. You'll need the 68-70 Mustang radiator and brackets.

As for power, a well-set-up 390 engine will have scary power, easily enough to revoke your license.

 

Cool idea. I wondered about doing that to my 67 vert. I have a fresh 289, wish I'd kept that completely rebuilt 390 several years ago.

 

What heads? What did the engine come out of? If it doesn't have the unit body style heads you may run into issues with exhaust, although 67 it's hit and miss whether the vertical exhaust bolts hit the towers. You will need headers or the correct manifolds. The oil pan will be an issue if it's not from a Mustang or Fairlane or the Metcury counterparts.

 

As far as weather to make it a 428 or leave it a 390. Is there much to gain or is the gain already enough from the 289 to a 390?

As previously noted it depends what you mean by "a 428", there were many different versions in that displacement.

If you start with a more common 390 block and add a stroker kit and mild upgrades (see Survival Motorsports Home Page) you can make more Hp and torque than most stock 428's. Upgrade the cam, other bigger/faster bits (heads, intake, headers, etc) and you can go to 600+ Hp without too much trouble out of a 390 (but lots of $). 400+ is not hard to get to...

Anyone who did such a swap and built a 390 to stock specs would be somewhat silly, unless you had the complete and running engine to drop in (nothing wrong with a stock 390, they do go pretty well). To rebuild a stock 390 or go with upgraded cam, heads, intake is not a big $ jump. A stroker is a bit more, but if working from a bare block again not a huge step change in cost to go stroker crank/rods/pistons over stock, and "bang for the buck" can be had quite easily.

if you want "a 428" as original then it has value as "a 428"... but as its a swap the advantage of a true "correct" 428 is lost in comparison to doing it as a recreation of factory in a "matching numbers" car.

IMO for a swap from a 289 to a stroked 390 will get you pretty much to the same place as a true 428 block for less $ if a specific HP/torque goal is in mind... for a restomod not a lot of value in a "428"...

 

Also, if you have an early 390, there will be only two bolt holes on the block fir the engine mounts, that will require modification of the engine insulator brackets to get them to work.

 

If you do use the engine, it will be cammed for the station wagon, which is great for hauling kids or pulling a camper, but lousy for digging out at a traffic light in a Mustang. You'll need at least the C6OZ-6250-B, which was used in the 390GT and the 428 CobraJet. Yes, same camshaft in both of those engines. That should make you feel better about leaving it at 390 cubic inches.

 

Think of all the problems that you think you will have doing the swap and then multiply that by 10.

 

289-390

I think it would be helpful to lay out your complete plan. Just dropping a heavily used 390 into a 67 coupe probably won't yield much over a worn out 289 that the car is currently set up for.

As some have mentioned, the 390 engine fits, but there are a number of changes/parts that are required and it can be quite expensive.