so i've heard ytou can bore/stroke a 351w up to a 427...now originally i descided i want to stroke my 302 out and built a badass lil 347...but i've heard about the size potential of the 351w and then this guy with a 67 falcon comes into my work and we're shooting the **** and he happens to mention he has a complete 351w sittin in his garage that he might let go for real cheap...and that got the wheels spining in my head that just tell me a 427 comet would be badass... opinions...? info on the 351 to 427 transformation...?
the 351s can be made into several different sizes. Requires different crank, rods, pistons and I think some block clearancing. If you don't have the shock towers cut down then it will be a PITA to work on, and still not so much fun even with them shaved. The 351w swap has been done many many times and they all suggest a minimum of cutting the shock towers back. If your funds are unlimited Id go for it but I'd swap the frontend to a MII setup also. Goodluck with whatever you may do. The Complete 351 wont help you anymore than a block would however. You'll be replacing everything internal, and most likely have to get a different oil pan at that.
I have a 351 in my 72 Comet and we cut the shock towers. The headers are the tough part, the pipes want to come out right into the upper A-arms. It is very tight. Other than that, changing the plugs is a walk in the park compared to the stock 302 and uncut towers. Also, it is tough to get a 351 to fit under the hood with anything except a short intake. My air filter is in the scoop opening. A 351 only weighs 40 lbs more than a 302, so an aluminum intake negates that. I would lean toward doing a 393 stoker for a 351. You can use 302 pistons in it rather than custom stroker pistons. I believe the 351 rods work in this too (I need to look it up again ...), so you might get away with only buying a crank. Not as much block notching to do either. All that being said ... I will be yanking my motor out soon to check its condition. If it is anything more than a simple rebuild, I might go 393, or I might opt for a 347. I am on the fence right now. These are very light cars, and geared well, a 347 would probably be a screamer and would actually fit the car well.
427 can be done with a Windsor, but like said before, you really only need a good block. Everything else will pretty much need to be aftermarket. Even the heads should be seriously upgraded to feed that many cubes. The 393 uses many stock parts, and is the least expensive. Stock build with only an aftermarket crank needed. (and 302 pistons) The 408 is the most common. Middle of the road pricing, with great power. 427 is possible like you say, but it really is the extreme edge of 351 builds. There is another combo that is pretty extreme too... Not very common. It's around 418-420 cubes IIRC.
You may want to double check this but I think only some of the blocks can be punched out to 427. I think it has to do with the deck height and the way the water jackets are. I know FRPP sells some 351 blocks that can only go to 408 and some that can go to 427. One of the guys in my mustang club just finished a 408 using a 351W out of a '90 F250. He picked up the used shortblock for $150.
The very early blocks, I believe just 69 and 70 had a bit lower deck height. I would have to check to be sure, but I think it is around .010 shorter. Later blocks can be decked to the earlier spec to gain back some compression. My block is a '74 and I am planning on doing this.
You can do 427 with a stock block. Just a 4" bore and 4.125" stroke. You'll have pistons that are really short (but light) and it'll need lots of clearancing, similar to a 347 but it works. A more popular option is the 408". 'Course there is also the 393 but by the time you have the stock rods upgraded and get a set of pistons, you probably could have just gotten an Eagle "kit" which is already balanced. Chinese stroker kits are going for under $1000 now with some even less! The biggest problem is packaging. Making a 351w fit isn't easy. It's do-able but not easy. This is where a 302-based engine is really a better choice for most street cars, and a 347 or 355" stroker is plenty capable of 500+ horsepower if it's built right. IMO, the best bang for the buck is the 408" windsor. Simple to assemble (very little clearancing is needed) and plenty capable of some serious horses. If you go with an aftermarket block, you could go up to about 470" with the right bore and stroke combination. Oh I almost forgot, a 454 is also do-able with a dart block. Imagine telling your friends that your Comet has a 454.
Thanks for the info. People about had a stinkin heart attack when I told them the motor in my 66 F-100 was a 396. Course it actually was one, but it was an FE and not a Chev-ro-let
