6 cyl to 8 cyl cars

[Toughlou]

I previously owned a fox mustang and sold it. My next mustang preference is a 65-69. I see many for sale very cheap that are 6 cylinders and a few 8 cylinders. I know its common to take the 250 out and put in the 302.

I'm new to this but have done some research but please help. Is the 302 from the 60s mustang just as powerful as the 302 in the fox mustangs (225 ponies?) Does it make sense to put in a fox 302 into a 60s mustang and what kind of transmission upgrade is needed?

Do the 6 cylinder cars need extensive changes to be able to handle the power since they were built for 125 horsepower and now the power is nearly doubled.

Thanks

 

[88 Fox GT]

Yes, the late model 5.0 is more powerful than the 60s 302. It is a fairly big project to change from a 6 cylinder to a V8. All the suspension will need changed, but other than that there is really no strengthening needed. Just heavier springs, and 5 lug suspension along with the steering parts to go along with it.

 

[Toughlou]

I'm concerned about frame twisting as well. Any other major things to tackle in the engine swap?

 

[TheWolf]

It makes more sense to me to pick up a V8 car to start with. For the 6-8 conversion, if you drop in a stock 289/302 from the 60s you will most likely be disappointed (unless you find a k code or something). If you get a car with a 250, it has a v8 bolt pattern so you could keep the same transmission (not sure if thats wise), if its a 200 you'll defentally need a new transmission.

 

[brianj5600]

It is not hard to find people here with cars that have modified the motor, radiator, trans, rear end, suspension, brakes, etc. My plans are for all of this so it works out for me to do a 6cyl to v8 swap. If you just want a cruiser, buy a v8 car. If you are modding everything and can find a solid 6 cyl car cheap, snag it. 64 - 66 6 cyl cars have different front suspension and steering parts so they are a little more involved.

 

[Ozsum67]

I would like some info on an 8 to 6 swap. I'm tired of 5 lug wheels, all that power, heavier suspension, etc. Can anyone help me?

 

[TheWolf]

I would like some info on an 8 to 6 swap. I'm tired of 5 lug wheels, all that power, heavier suspension, etc. Can anyone help me?

You laugh, but someone did that in an old article in M&F, only he added a supercharger to the 6. I'd have to dig though the old issuses to find the exact dyno numbers but they were darn good.

 

[67GTFastback]

I would like some info on an 8 to 6 swap. I'm tired of 5 lug wheels, all that power, heavier suspension, etc. Can anyone help me?

Oz, you might just want to swap your car with my 6 cylinder, the suspension and transmission will all have to be converted and the parts for the 8 to 6 conversion are very difficult to find. This one is a real beauty, 4 lug wheels, manual steering and brakes, all original and unrestored. Here is a picture of it:

 

[Pakrat]

As many things, it will boil down to opinion (wildly varying ones at that) and personal preference. I am in agreement with most where as if you fall into the group that is either looking to replace everything power orienterd anyway, or you have some type of long term sentimental attachment to the car (ie: it was your grandpa's grocery getter or your first car as a teen or it is a basket case no one normally restore) then go ahead and modify it to suit your current needs or tastes. If you are simply looking to spend less up front but are afraid that the 6 is too weeny for you, then bite the bullet and just purchase an 8 and be done with it. When these cars were but 10 to 15 years old, many got basterdized and messed with, now that they are true classics, it just makes more sense IMHO to preserve the ones you can regardless of their option list if they have in fact survived this long unaltered. Kind of like having hunted a species at one time to near extinctsion and then suddenly struggling to preserve it. Naturally their are many out there who only care about their own needs and would argue that their car is theirs to do with as they see fit no matter what that it is and they have a valid point also, so you really just need to decide how you personally feel about it. Are you loyal to the Mustang and looking to be a responsible caretaker of a piece of automotive history or are you in it purely for the looks and flash and just want soemthing hot? Once you decide the particular type of stanger you are or exactly what your needs for the car are, then the rest will all fall right into place.

Good luck whichever path you take!

 

[Toughlou]

My goal is to make a 60s 6 cylinder mustang a low 14 second car. I was hoping a fox 302, new transmission and some small power adders would do the job and the car would be able to handle the muscle. By looking at some pics the car would definetely need some better tires!

 

[63_Fairlane]

I think that type of performance should be easily attainable. The things to consider are the parts that need to be changed out to properly back up that V8.

Check out the FAQs in classic talk. There is a good list of the stuff that needs to be changed out.

 

[bud168]

Once you start going faster then you have to worry about braking and all that good stuff.. I am in the process of converting a 64 Falcon to V8 which is very similar to the mustang frame.. I am in the process now of upgrading to disk brakes and V8 Steering in the front and a bigger rear in the back probably a worked up 8" rear.. Im putting in a 289 with C4.. The nice thing about the mustangs are the parts are readily available, my falcon parts are not as easy to fine.. I think with a mustang it will be pretty easy to upgrade most of the parts.. I kinda wish I had bought another one of them.. i wante to be different.. Good luck!!!! And have fun

 

[bud168]

Once you start going faster then you have to worry about braking and all that good stuff.. I am in the process of converting a 64 Falcon to V8 which is very similar to the mustang frame.. I am in the process now of upgrading to disk brakes and V8 Steering in the front and a bigger rear in the back probably a worked up 8" rear.. Im putting in a 289 with C4.. The nice thing about the mustangs are the parts are readily available, my falcon parts are not as easy to fine.. I think with a mustang it will be pretty easy to upgrade most of the parts.. I kinda wish I had bought another one of them.. i wante to be different.. Good luck!!!! And have fun

 

[pabear89]

Pak, slow down and take a breath.
Yea there are some of Us that have that one car that has been in the Family from the start.
You want a Quick Cruzer.
Then Start with a V8 car and bolt on your Additives.

But if your going to go with a Full Change over of a 6er,
As in Stroked Big block or the 450+ Hp level.
Then grab out the best Bodywise 6 or 8,
You would be upgrading the Susp and Brakes anyway.


My 2cts and the Voices

PB

 

[CochinoFilipino]

Has anyone actually witnessed or have first-hand knowledge of a V8 causing problems with the original 6cyl suspension components? Or are we just passing along what’s been read in some magazine article and posted by others?

I wonder how much power the 6cyl stuff can handle.

 

[TheWolf]

I've seen cars that have had a v8 dropped in and still had the six parts in there on the internet. As long as the v8 was a stock weaker version, I guess it wouldn't tear it up. However, the increased weight would maker harder to stop. The best bet is convert everything over, If you're bent on converting a 6 to an 8.

 

[Pakrat]

Pak, slow down and take a breath.