I have a 1966 Mustang (notchback). It's a I6 engine, original. I want to feel more pep in the start (off a light) and the 35-45 MPH range for street enjoyment. No racing. I can get a 351 Windsor for $500 with a transmission. Also available is 289 or 302. Which should I go for?

 

The 351 sounds like a damn good deal!

 

I'd go with the 351W and possibly stroke it out. Most definitely will feel more pep and it'll be a monster off the lights with all that low end torque.

 

This comes up so much every month lol.
Its all a trade off. 351 more power will most likely break everything in line behind it.
I had a 289 mustang factory 4 speed.
I built it into a lil torque monster for what it was.

Count on the trans, drive shaft and rear end getting upgraded or they will break.
Your 6cyl radiator wont be enough to cool the engine either.
Brakes or important the 6cyl drums are a risky thing but not getting into a safety debate cars had them for years.
I just like to stop faster if my car can go faster.
Just know what your getting into. $$$$$

Still every-time this topic does come up I give the same advice.
Gears, gears ,gears. And a trac lock of some sorts (posi)

411 gears on that lil 6 will still get out and go.
Then you have to deal with high rps to cruise @ the speed limit on highways.

I dont know what your cash flow or idea of what you want from your car is but...,
Gas is killing me these days!
IMHO a good tuned 200 6cyl with a T5 and a 373 gears with at least some 15" tall tires would be a nice trade off these days between
performance and fuel costs.

Having said theses things mine are all v8s lol

 

You need more then a engine and tranny.You need the v8 spindles hubs brakes front springs and steering linkage 8 inch rear end.

 

Find a 1985 or newer 302 with the hydraulic roller cam and put a carb on it.

 

Geez, if you don't want racing, why in the world would you get a 351. The 6cyl can be a lot of fun, and it'll cost you less in the longrun (at least, when compared to the 351...)

Get the new Aluminum head from Mike over on www.classicinlines.com and you can throw a 4bbl carb on there, good cam, open up the exhaust a little with some headers, and you've got a mean machine.

 

Having done a 351 into a 66 "the right way", I can say that it is not a hard swap for a person with reasonable to good mechanical aptitude, but it can be expensive as the list of parts that should be changed is long. We bought a lot of brand new parts on ours. The swap can be much cheaper with the right "donor car". (talk to TexasAxMan about this)

If your 6 cyl has a lot of rust or you will not be able to do the vast majority of the swap work yourself, then I strongly advise against the v-8 swap.

A 289 or a 302 is easier than a 351 due to header and hood clearance differences, but these are notbig obstacles to overcome.

Be wary of the tranny that comes with the 351, a C-6does not really fit in a 66.

<<Oh yea, my son really digs his 64 Falcon with it's stock 6 cyl & C-4.... he spends a lot less on gascompared to his 450 HP V-8 truck..... and the little Falcon still does mid 10's in the 1/4 mile...

 

WINDSORRRRRR FTMFW

 

in case it's not clear from the posts above: a 289/302 in the front will cause the rest of the car to fall apart.
If you go for V8, then you need to do a complete swap as pointed out by others, or you just break other parts of your car, or worse: yourselves. if you don't want racing, just something peppy, then I'd rather leave the I6 in there and go with other suggestions