351 Windsor Swap

Ok, so to quote myself:

...it's time to pull this engine. If it weren't for the knock I'd say it's time to just freshen it up, but I'd need at least some of a rotating assembly, plus new rings at least assuming the bores aren't messed up, along with whatever else I find. All that work, money and uncertainty just to be right back where I was to begin with after it's all done. Hence I start to think about mods, or or even another engine. The 351w swap starts to make sense, especially when I can go inspect it, hear it run, etc. and for the price I'm paying. If the engine turns out to be as good as I'm told it is, I'm making out pretty well. (I'll tell you after I go get it. )

I've already made arrangements with Stefan to auto-ban anybody who types the numbers "3-4-7" in this thread, so don't. And if you want to tell me why I should be doing something else instead, do it in another thread or PM me. This thread is about gathering information and posting progress related to my 351w swap. Hijackers will be sent to Gitmo.


...Alrighty.

Here's what I've got so far. Questions are in red.

The engine I'm getting is supposed to be a good runner, no smoke, good compression, oil pressure, etc., and I'll get to verify all that Saturday so I feel pretty good about the condition. It may or may not have been rebuilt. The seller feels pretty certain that it must've been, but doesn't know anything for sure. He bought the truck to part out. I'll be opening it up and checking out the bearings, will give the cylinders a hone if need be. I'm hoping to avoid the machine shop but I'll go there if I have to.

The truck is a '79, so I will assume the engine is also until I get the casting numbers. This would mean it's a low-compression smogger if it's stock. (When I put the compression gauge on it, what numbers should I look for?) If the heads are smog junk I'll look for a pair of E7's, GT40P's, or I might even use my current small-chambered 302 heads. (I know I'll have to drill out the bolt holes if I go that route. Any other mods or concerns with using 302 heads on a 351?) ...Obviously if I find out the valves in my heads are smaller I would use something else. Anyway I'm thinking closed-chamber 302 or GT40P heads would raise the compression level up to something acceptable even if it has low-compression pistons, right? Can I use my 302 pistons if the bores are the same? I've read where some people say no, I've seen some say yes, and I've seen pistons listed for both.

The engine comes with an aluminum four-barrel intake, so that's covered. I believe I'll need to get a front-sump 351w oil pan because the 302 is not the same, right? And of course there's the optional but highly recommended shock tower shave. I'm under the impression that I can reuse practically everything except the intake, distributor and oil pan from my 302 when it comes to actually getting it in there, including the (28oz) balancer and flexplate, yes?

My cam is a Comp 268H. (specs here) I know I can use this cam if I switch to the 302 firing order, but are these specs suitable for a 351? (I also have 1.7 Comp Magnum rockers, so the valve lift is actually more like .484, not .456.)

My accessory brackets... Pretty sure I can use what I've got and just get longer belts, right? How about the AC compressor bracket? That's a stock Maverick part. Do I need to go find a York compressor bracket from a 351?

Exhaust. I know this sounds awful but I'm going to use my 302 Manifolds for now. Ultimately I know I shouldn't, but for now I can, right? Don't worry, headers are in the future, but for now I just need to get this car back in service.

The dipstick tube for this engine is probably not in the right place, is it? Can/should I reuse the timing cover from my 302? Can I just drill the one on the 351? Or is the dipstick location a non-issue?

Going to pick up my engine on Saturday, will post details when I have them. I plan to listen to it, look at the oil and water, look in the valve covers, check the compression, check the oil pressure... Anything else I should look for before I buy it?



Guess that's all I have right now.

 

good choice! iv got a 351 windsor in my comet !! trust me , it will last foreverr!! n the powerr whooooohhh!!

 

Oh, my. I've just started reading about 3.85 inch cranks... They are cheaper than decent 351w pistons.

 

ahahaha! i ran the crap out of mine n it never blew up or anything. i just recently rebuilt it an put a medium cam and flat top pistons

 

Cool, what kind of cam do you have now? What did you have before?

Was just checking out your pics. Very nice. But they make me wonder if I'll have any trouble with the power brake booster clearing. Anybody know?

 

I think 79 was around the time Ford went back to flat tops. And to compensate they went to huge chambers. The specs on that 351 should be 69cc chambers, 1.78/1.45 valves and 8.3:1 CR. Now the GT40P look like the best choice. They are the best flowing OEM head, should have around 60cc chambers (some have as small as 58), 1.84/1.46 valves. Of course there's the plug issue. But here's where it get's interesting. With stock manifolds they turn down from the exhaust port, so there shouldn't be an issue right? Then take a look at crite swap headers....the tubes point straight down also(unlike 302 headers that sweep back). So just by looking at them it look's like they'll clear too......Now the power brake's thing. A 351 has a taller deck by 1.3"s. So wouldn't that measurement (from your valve cover to booster ) give you a somewhat good guess? Again these are just idea's i'm not entirely sure.

 

And I plugged in the numbers on my CR calculator. Assuming it has flattops with 69 cc chambers, a swap to 60cc would bring up the 8.3:1 to 9.03:1. If the head is 58cc would be 9.21. Now If you mill them to say 54 you'd get 9.6:1, right in the sweet spot.

 

I think by 79 they went back to the smaller valves in the 351w heads, or just used the same as that year 302 heads. You will benefit by usuing your heads you have now with the smaller chamber and will have the same valve size. Plus you know they are good so will cut down on cost of fixing up the other heads.

Timing cover should be the same.

You WILL need a windsor oil pan.

Brackets will not work on the ones that bolt to the head and water because of the different head height. use the Windsor brackets.

 

Correct

 

Good stuff here, thanks. If you're right about the specs then the valves in that engine's heads are no bigger than the ones I have in my, 302 heads, possibly smaller. So I'd be making no big sacrifice there if I decided to use them, but the compression should go up. The only thing I know about my current heads is they're "small/closed chambered" and they were cast in '72. Will know more after the autopsy, of course.

If the pistons are flat tops, I'll be set, no? And if they aren't, then I could either buy a set of pistons or use my 302 flat tops along with a 393 crank. Hopefully that wouldn't bump the compression up too high. (How high is too high? I already can't run 87 octane on the 302.)

I think the brake booster will clear, now that I've looked.

 

Thanks for the info. That's about what I was figuring, nice to have confirmation. Now depending on how much money this project snowballs into I may be able to go ahead and get some headers. I don't dare go ordering them yet though.

So when I go looking at the junk yard for my AC bracket, is the 351w the only engine it can come from? How 'bout an M? Same deal on the oil pan?

 

Oil pan is 351 specific. Timing cover should work fine from the 302. The 392 I built for the 'stang is running dished pistons(9.8:1 CR) with GT40s. I'm pretty shure the 302 flat tops will work, but the CR is gonna be pretty high if you go that route.

Don't forget a distributor!

 

So basically when I open this thing up... If it has flat tops, leave them there. If it has dished pistons, then I can either buy flats or use my 302 pistons with a stroker crank. (about the same price, really) And as for the heads, use the big chambered ones if I end up going with a stroker, small chambers if I don't. Sound right? Or am I good on compression if I use dished pistons and small chamber 302 heads? Is that a horrible idea?

And I think I'm gonna have a distributor already. Seller is going to let me hear it run before I buy and he's including the intake and even the carb, so I bet that'll mean the distributor too. Probably a DS. If it's in good shape I'll just hook that up to my MSD 6a, buy a nice hot coil if needed and that should be it.

 

Nobody's said anything about the cam yet. I think it's a reasonable spec for this engine in a driver, right?

 

Not sure on the cam, but it will most likely have dished pistond. Keep those and your 302 heads and you are good for around 9:1, if it has flats your are looking around 9.6 if I remember on my old setup with similar heads. If you are already running high octane anyways it wont get any worse either way. I run 10.5:1 and run 89 or 91 octane depending on my wallet. SO why would you bother with a crank? if this is a driver its just spending unneccesary money. if rings and hone are good leave it all alone and use your cam from your old car if you like the power it made, it will only make more with the extra 49 cubes.

On the duraspark dist with an msd box: my experience is it works, but not great. I picked up some power and better throttle response on going to an MSD dist. (no vaccum advance model) with the MSD box i was already running. Spend the money there instead of on the crank or pistons. it's been problem free for 10+ years.