[capkangaroo]

Hello,
This is my first post so I am not sure if this is the right forum for this, but here goes.

I just purchased an early 1965 mustang (1964 1/2) with the 170cui 2.8L engine and C4 transmission. I was originally going to leave this engine in there as it was the original for this specific vehicle, but found later that the numbers don't match so I thought I would change to a larger engine. I have a 351w sitting around that I am really considering because it will bolt right up to the C4, but I am unsure of what suspension modifications I will have to make to compensate for the added weight.

Will I have to change the springs or can I just add spacers to lift the front end with the added weight? Will I need to install a front brace/cross member in the engine compartment? Should the drive shaft and rear end be changed or will they be alright as is? Anything else that you can think of would really help me out even if it isn't suspension related. I have never worked on a mustang before so this is all new to me.

Thanks

[wolfdog]

To go to a V8 you will need to change the radiator, Front brakes, Better to go with dic brakes, Will need to change front springs, get the 5 bolt hubs with spindles. Some say you do some say you don't with rear end but I would get a bigger one. throttle linkage for a V8, not sure on witch front end parts you will need.frame mounts and motor mounts for a V8. I am sure I left something out.

[sixtsixstang]

I6 to V8 includes changing motor mounts, radiator, throttle linkage, tie rods, tie rod sleeves, center link, spindles, front springs, idler arm, pitman arm. Front and rear brakes will have to be changed out, (drums, etc.), to a 5-lug set up. Might as well get an 8" or 9" rear end to hold up to the larger engine. As mentioned above, disc brakes are an excellent option if you have the extra cash. While you have the front end apart, check your upper control arms and shafts. Good idea to put new shaft kits in them if it hasn't already been done. At this point, you should replace ball joints, lower control arms and any bushings on your strut rods and sway bar. And then of course have an alignment done. There is alot to it but it is not that hard to do. With all the parts on hand, I did it to my '66 as a week-end project.

[Chuck M]

The deck height on the 351W block is higher too which results in some very close clearances to the shock towers. It certainly can be done but will require a set of headers dedicated to this swap. Another option is to trade your 351 for a 302 (5.0) or a 289 at which point it becomes a straight bolt in swap once you accumulate the correct pieces. The front springs definitely will have to be replaced with V-8 coils, but the cost isn't bad. Five bolt spindles with, at the very least, the bigger drum brakes are in order. Disc brakes would be better. The original 7.5 differential would hold up to a stock motor if you didn't beat up on it too much but a tire and wheel combo with the 4 bolt pattern is hard to come by. Better to upgrade to the 8 inch differential with the five bolt axles. These are readily available and inexpensive. I've been running 325 rear wheel hp through mine for years with no problem. As with any modification other things will pop up. As they say, speed costs money. How fast do you want to go?

[thetvirus]

I believe the guts of a 6 cylinder C4 and the 8 cylinder C4 are completely different, so a 6 cylinder C4 behind a 351W would not last very long.

[capkangaroo]

Thanks for all of the replies. You all have really given me a lot to think about.

New question.....If I were to change my plans to a 289 instead of a 351 would the changes to the suspension, rear end and transmission all still be necessary or only a couple things as the engine would be considerably lighter and less powerful? Thanks

[sixtsixstang]

Yes. Still the same conversion. Not sure about the C4. As far as I remember the tanny is the same for I6 and V8. You may just need to swap the bellhousing for that.