Plan D opition....

good news...you can find roller 351's all over online! They're out there, and affordable.
Bad news and take it from me cause I have run a 351 with gt40 parts before,
you are going to get 302 power from that 351 if you bolt those gt40 parts on there...it will make more torque than your 302, but thats about it. The 351 lightnings were rated @ 240hp I think, that's because Ford threw gt40 stuff on it and it couldn't breathe. IF you go the 351 route which I think is a great idea, take the time to find heads/cam/ and intakes that will flow enough for the 351 to shine. You won't have to break the bank either, but used stuff that is cheap and you will love your 351! If you bolt that tubular gt40 crap on that 351, you will be killing the potential of that motor
End of Rant

try the corral, there are always shortblocks for sale. Did you check stangnets classifieds? Or just google 351 windsor for sale

you do know you'll also need conversion parts for the swap right?

Excerpt:

The advantages of using a 351W vs a 5.0 (302):

FIRST, you get an extra 49 cubic inches of displacement. As the saying goes, there is no replacement for displacement. Second, the webbing in the lower half of the block is thicker, making the block stronger. Third, the crank has bigger main and rods journals, making the cranks more durable than their 302 counterparts.



FACTS: What you need to know/consider when you swap a 351W into a Fox platform chassis:

A 351 block is very similar to the 302. That means that almost all parts swap between a 302 and a 351. This includes: Heads, cam, lifters, timing chain, timing chain cover, water pump, engine mounts. The bellhousing bolt pattern is the same as a 302, so all trannies that bolt to a 302 will bolt to a 351.

Swap Parts Needed:

1. The oil pan is different. You can also get an oil pan of of an early eighties 351W LTD Crown Vic. If you go the junkyard route, remember you also need a oil pan pickup tube, and a special main bolt that the pickup attaches to. The FRPP pan is a pretty good deal, and if you shop around, which comes with the dipstick, bolt, and pickup tube.

2. The internal balance of a 351W is the same as pre-81 302's (28.2 oz). The 5.0 HO has a 50 oz. unbalance, which means you cannot use the flexplate/flywheel or the harmanic balancer off of an HO engine. You have to get the correct pieces from a Parts Store or junkyard.

3. The deck height is higher and wider, which means you need a 351W Intake Manifold.

4. Also, a higher deck height means that the accessory bracket will need to be replaced. FRPP sells the new bracket for about $50.

5. The higher deck height means the headers sit up higher than in a 302 powered Mustang. A special set is required for a 351 (BBK or MAC makes really nice headers) 302 WILL NOT WORK!

6. You mayl need a cowl hood for your car or you can space your K-Frame down to clear your stock hood.

7. The distributor has a larger oil pump driveshaft. You can obtain one from a 351W powered FI truck (if you are using FI) or if running a carb, any late 70's/early 80's car using the 351W and a Duraspark system.

Those are the major differences. As you can see, for about $1000 you can put a 351W in your Mustang. This is cheaper than a stroker, plus you wind up with a more reliable engine.

Tips: There are several things to look out for to ensure that your swap to a 351W is easier and more successful. They are as follows:

1. A high volume oil pump WILL NOT clear the FRPP pan. If you want to run an HV pump, you must either modify the pan or buy a Canton or similar pan, for many dollars more. The modifications just include cutting down the front drain bolt, and welding on a corner to the pan to clear the pump housing.

2. Get new motor mounts. The additional weight of the 351W will make old 5.0 mounts go bad in a hurry. Recommend are the 87-93 convertable mounts, which will work in any 79-93 Mustang K-Frame (4, V6 or V8 stlye)


87-93 Fox Mustang 5.0 to a 351W Swap

ok, you need to ask your self how fast you want to go. Everyone needs a power goal. I say this because it sounds like you have a decent 302 with decent heads and intake and you were looking for a cam swap at first? Going from a simple cam swap to throwing in a 351 that you still need to find and buy and put in is a giant step. Then you mentioned you already have a supercharger? Im sorry, but a 302 with gt40 heads, ported gt40 intake and a custom cam (or AMS cam) with a blower will be a blast on the street! It will make good power.
I think it comes down to this.....if 500 HP will float your boat, keep the 302 and get the perfect cam for what you have.
If you want more than 550hp, find a 351!

I just read your "plan C option" If your goal is 12's, keep the 302, keep the heads and track heat intake, get a nice cam,
you will have the power to get into the 12's EASY, now your chassis and possibly driving will determine if you make your mark. I would invest in your suspension, some stiffening, some sticky tires,
12's should be a walk in the park

I would honestly go that route, you will be on the street alot sooner too. put the 302 in after you install a nice cam and enjoy it. Keep your eyes open for a 351 roller shortblock this season, gather all the misc stuff and make it a goal for next winter even? Plus, if you take your time, you can find great deals on used heads, intakes and such for the 351. I pretty confident you will get into the 12's...you have the power, you just need to get that vert to put the power to the ground. A nice cam, appropriate torque converter, might want to go up to 4:10's, and traction= your goals