[howlitzer]

I have a 1969 fastback Mustang and am trying to evaluate which motor to put in it. I have a 351 Windsor that can be modified and a 429 from the same era. I would like to see 450 horses and know it's easily attainable with the 429 but am concerned about clearance issues. Does anyone have any experience with this and could offer suggestions?

Thanks

 

[Ashlander]

There shouldnt be any clearance issues with the 429. I knew a guy that had a 70 coupe with a 460 in it.

 

[stlwagon]

Welcome... We'll get you some advice in here.

 

[Dave]

I guess I'd have to ask first all the intended use, a DD or something for the strip. I'd go with the 351 or stroke it if it was my choice and money. Not sure how well the 429 would fit in a '69'.
Dave

 

[howlitzer]

It would be nice to hit the dragstrip occasionally but I have an '84 for that with a 347 stroker. I would like something that is dependable and will get after it upon request. I'm also concerned about changing the suspension and steering as well as the fitment.

 

[andrewmp6]

The 429 will fit but its kinda tight tho.I would use the 351w its easier to efi and is a smaller.

 

[Doc4421]

I've liked the 351s I've had (even if they weren't in a Mustang) primarily because they're strong, tight and they move like fury. When engines go bigger than that (friends cars) I've found that you can start tearing apart other crap in the car simply out of the power of the engine.

If you want to have a huge engine to say you've got one, the 429 is the way to go. If you want to cook around town, I'd go with the 351.

Doc

 

[sic65stang]

The 429 is tight, the way you can stroke a 351 could make it attain your goals and it would rev faster easier. I guess it depends if your building a street or drag car. Also the weight of the big block is going to make the car react differently, so if your in a more curvy part of the country, the small block would make the car a bit more nimble with less modification.

 

[howlitzer]

Thanks for the input. It sounds like there are some good stroker packages out there for the 351w like the 392 and 408. Do they have side load issues like the 347's do?

 

[86967]

If you use an aftermarket block the sideload issue shouldn't be a factor, I'm building a 427 stroker351w using an RPM block...650hp: is that enough for you? Don't forget the cleveland, its another great motor if you have the gumption to build one. You have to decide the use and budget for the car...the 69 is great because it can take almost any drivetrain.

 

[Trojan Horse]

The 429 is doable, but it is an extremely tight fit and will make the car front heavy and not handle very well.
You will either end up having to use stock exhaust manifolds, specially built headers and/or cutting the shock towers for side clearance.
You will also have to modify or replace the hood for carb/air cleaner clearance.

The 351W is the better choice, can be built to meet your horsepower needs and you will retain your front to rear balance and handling.

Check out some engine packages from Keith Craft to see some achievable horsepower ranges.
Keith Craft Performance Engines - Our Engines

 

[1978CobraII]

The 1969 came stock with a 429 CJ. It is a tight fit yes but the 429 is going to give you the nostalgic feel.

 

[Red&Ready]

The 351 can make as much power as you seem to want and at a much lighter and easier to work on package, not to mention parts availablity. I personally like the 427 stroker setup. Loads of torque and a lot of usable horsepower and it has the magic of the "427" designation..
The 351 is a no brainer to me.

 

[Trojan Horse]

The 1969 came stock with a 429 CJ. It is a tight fit yes but the 429 is going to give you the nostalgic feel.

True, the 69 also came stock with the 351W too though. :bigthumbsup

 

[andrewmp6]

67-70 both big blocks are a tight fit kinda a pain to change spark plugs on.The 71-73 was the best for a big block tho.I say 351w for a few reasons its cheaper to build a small block over a big block.You can use oem efi if you want efi and a t5 or aod will bolt right up to it.But its your car if you want a big block go nuts and get one.