351C Engine Swap in a 1970 Coupe

1970coupe · 12-06-2010, 02:56 PM

Well i have a '72 351C and i would like to put in my 70 coupe. I currently have a 250 6cyl with a T-5 Tranny. I am wondering if i will have to change anything major when i do the swap? I already know the motor mounts, but would i have to change the radiator? Also is their any way to beef up the T-5 Tranny so it can handle The HP and Torque? Any information will be very helpful!

david01130 · 12-06-2010, 07:14 PM

What kind of T-5 is it? The bellhousing might need to be changed to adapt the V8 to the tranny. I am not sure how the 6 cylinders were set up in 72 but sometimes the suspension (such as sway bars and springs) was stronger on the V8s to handle the extra weight. You can probably wait until after the swap to see what is needed. You may want a bigger radiator although I believe a lot of the 60s mustangs used the same radiator in their I6 and V8 engines.

1970coupe · 12-07-2010, 09:37 AM

Well the T-5 came from an 84 Mustang with a 4cyl turbo motor! The T-5 currently has an adapter on it that converts it to the small block bolt pattern. I was also wondering cuz i think the 250 6 cyl shared the bell housing from a 289 and 302, would it even fit on a Cleveland? Thanks for the reply David!

david01130 · 12-15-2010, 05:03 PM

I did some quick research on this. It looks like they all may have the same bolt pattern. As far as the early 289, 302, 351W and 351C. The difference between the 351W and C is that the C has different heads on them. I believe they are wider and some people I believe had trouble fitting them into 65-68 mustangs. But I believe the only difference between a 351 and 302 is that the 351 has a higher deck height therefore a longer stroke to make the 351ci. But I believe they have the same bolt patterns. I am not 100% sure on this but thats what it looks like.

Oh and also I believe the water flow on the 351C is different from the 351W.

BaddGT · 12-16-2010, 02:08 PM

The Windsor is a small block; the Cleveland is a big block. Thus the wider heads. Don't know if the bellhousing from the T-5 would bolt up or not. If you're going to go through all of the trouble why not just pick up a C-6 and slap it in?

1970coupe · 01-01-2011, 07:51 PM

Im trying to make the car look stock at first glance! But i also wanna keep the T-5 for gas mileage purposes even though i know the cleveland is gonna get around 17mpg with the T-5! Also i ahte driving automatics.haha..i have looked into it and the T-5 Can bolt up to the 351C Cuz my bell housing bolts to the cleveland! The only question i have now is: is there anyway to make the T-5 handle more torque, i already know i should beef up the clutch!

david01130 · 01-02-2011, 02:12 PM

upgrading the clutch is probably the best place to start. Not sure what else you can do other than using good fluid and a solid shifter. I know some people have put in a stronger input shaft for more torque but that may require some custom work at a tranny shop.

1970coupe · 01-02-2011, 06:57 PM

Does anyone know by chance if they make 351C 2V headers that will fit a manual transmission?

Sick06Stang · 01-04-2011, 01:35 PM

The 4 banger T5 will self destruct if you put any torque or power to it with a v8.Unless you just plan on cruiseing and not banging gears i dont recomend it. Get a v8 T5 and rebuild to Z specs or get a tko-600. That will handle plenty of power.

1970coupe · 01-05-2011, 03:39 PM

Okay heres a a question about transmissions! Will a 4 Spd toploader bolt in like a T-5 or like the Original 3spd Manual? I know the 4 Spds can handle anything just about!