Sterling Pistons #381. Summit stocks them in .030 oversize for $10.99 each (#STL-381P30) though you can probably get them in .020 over as a special order. They are listed as "390 truck" pistons because they are slighly dished to keep the CR down. In a 390, they are listed as giving 8.2:1 compression. With a 428 crankshaft, however, you have a compression ratio between 9 and 9.5:1, depending on your head gasket and combustion chamber volumes.

Keep in mind that you'll also need a 410/428 flexplate.

 

I agree with Matt's post saying the 460 might be a better way than putting a ton of money in a 427-428. You will need a different tranny if you do the swap, it is worth it. I used to drag race the 428 very sucessfully. They are now more expensive and rarer to aquire. The 460 is easier to make more torque and is every bit as reliable dollar for dollar. Cost will be less with a 460 in general. Try to go to get a 427 or 428 at a wreckin yard! Generally the heads are better for breathing then a 428 in stock form. Do your research before you sink a dime in this project to compare things.

Happy wrenchin

Rob

 

I think you guys are missing Greg's point. He has a '69 F250 with a 390/C6, and the truck is in great shape. He just wants more torque out of the motor, especially so he can tow a large boat. His options are the following:

1. Fiddle with the 390, by changing cams, adjusting timing, etc.
2. Stroke the 390 with a 428 crank
3. Build a 428 or 454 (stroker 428) FE and swap it for the 390
4. Replace the 390/C6 with something else entirely, such as a 460

The first option is the least expensive by far and might be worth a few hundred bucks. Frankly, I think his cam may be a bit too radical for how he uses the truck.

The second option (stroke the 390) is the next most expensive. All he needs are a crankshaft, pistons and a new flexplate. Total cost for all parts is likely to be under $500, and he can do almost all of the work himself in his garage.

The third and fourth options require a LOT more work and a LOT more money. I agree that you can build a 460 (or even a 500+ cid stroker on a 460 block) cheaper than an equivalent 427/428/454, but why bother if he can get what he needs by putting $500 into his current engine? Besides the cost of building a 460, if he does he also would need new motor towers and mounts, new headers, a new trans, a new driveshaft, and lots of other things that he doesn't need if he just strokes the 390.

 

[updated:LAST EDITED ON 27-Sep-02 AT 07:09 PM (EST)]Lots of learning happening here, thanks! A few more questions.

If I change the cam to something milder, I don't really gain any torque, I just move it lower in the RPM range, correct? Keep in mind, I'm running 4.10 gears and 255/70r16 rubber, about 3400 RPM on the interstate.

If I go with the 428 crank, will the extra cubes and the longer stroke help compensate for Crower Cam? I realize a cam chamge is easy and cheap enough, but I do like the way this one sounds and I already own it and have just about 3000 miles of break in on it. Yeah, I'd like to have my cake and eat it to :-) My other concern if I go with a milder cam, then my carb is probably too big. It may be what's hurting me now anyway.

For 93 octane pump gas, should I shoot for compression of about 9.5:1 ?

For good torque, do the higher flowing Edelbrock heads help? Probably not at lower RPM, right?


Thanks Again.....Good thread so far.

 

I agree karl. I think the best option would be the 410. The 460 is a great motor and I have no complaints about it but to convert everything over is not only going to add up costs, its a pain in the rear. Edel heads on a 410 with 9.5:1 compression and a good cam will pull anything that is safe for the truck to pull. As you know gtex I don't like that cam you have but you can always change if it doesn't work for you. The cam I feel would be best for you is the 901 crane. Its going to give you a nice smooth idle, tons of low end grunt and enough top end to still make for a fun driver. Gas mileage will be decent for an FE anyway. The RPM heads don't flow so much that low end port velocity will suffer but I would not use the RPM manifold. An s code cast iron would be great. The performer would be better but more expensive. I think you are on the right track to having a great running motor for towing.

 

>Lots of learning happening here, thanks! A few more
>questions.
>
>If I change the cam to something milder, I don't really gain
>any torque, I just move it lower in the RPM range, correct?
>Keep in mind, I'm running 4.10 gears and 255/70r16 rubber,
>about 3400 RPM on the interstate. [SNIP]

Actually, a milder cam not only lowers the power peak, it also would increase your peak torque. Torque is a function of two things -- the force pushing down on the piston, and the length of the lever (the throw/stroke). A longer duration cam keeps the valves open longer, which allows the engine to breathe better. Those open valves, however, also allow cylinder pressure to escape, which decreases the pressure on the piston. It's a trade-off. Shorter duration means higher cylinder pressures and more torque, but also restricts breathing and limits high end performance.

>If I go with the 428 crank, will the extra cubes and the
>longer stroke help compensate for Crower Cam? [SNIP]

The extra cubes and stroke will compensate somewhat for an oversized cam, but a higher compression ratio will make the biggest difference. The higher your CR, the more duration you need on the cam.

>For 93 octane pump gas, should I shoot for compression of
>about 9.5:1 ? [SNIP]

With aluminum heads, 9.5:1 should be safe for 93 octane unleaded gas. You might even be fine on 87, depending on a host of other factors. I wouldn't recommend going any higher than 10:1, though, if you plan to do any towing.

 

Just tossing in 2 cents here.

I'm in favor of the 410 buildup, probably because that's what I'm working on. Soon as my tranny is rebuilt the engine goes together and in she goes. Can't wait

I picked out the sterling pistons for the lower CR with the 428 crank, and grabbed a set of adjustable rocker arms so I could put in a solid cam. Picked out the Erson E240025 TQ25M. If someone can run a dyno on it, should be able to show you the kind of performance you could look for. I was really happy with what I saw. RPM range is 2500-5500. Stats on the cam: 270 IN 280 EX duration 220 IN 230 EX .542" lift IN and EX, 110 Center. Should be 4 up, though with my timing chain I have to go 2. In any case, it has a very very nice torque curve and impressive hp when you go 410 03 over, 9.5:1, 750cfm carb, dual plane intake, well ported heads and large tube headers with muffler.

If I'm remembering correctly, without adjusting for altitude, and for my setup I should push over 450 ft/lbs from 2000-3500 and push about 410 horses at 4500-5000 (would be more but I'm not shelling out another 250 for a carb, stickin with my AFB 600 and compression may be off a bit, not that I'm terrible concerned). 'Course it'll run with the hydraulic crane pretty well too, if you don't want to go to the trouble of the head work. (my heads can handle up to 5.75" valve lift, and I picked up hardened rocker shafts as well. Don't want to break anything with that kind of lift)

Your cam may be fine, but I looked at a lot of grinds, and not all cams are created equal.

Anyone able to run him some evals and post 'em up? I don't have any hosting space or I'd do it.

 

>That's why Ford built both a 427 and a 428. .... The 427,
>however, was a large-bore/short-stroke engine, whereas the
>428 was a small-bore/long-stroke engine. As a result, the
>427 didn't develop a lot of torque, but it would spin higher
>and develop more horsepower, particularly at 4000+ rpm. The
>428, on the other hand, developed LOTS of torque from off
>idle up to 3000 rpm or so, but trails off after that and
>becomes a dog beyond 5000 rpm or so. The 428 was designed
>specifically as a torquer to move the very big and heavy
>cars Ford was building in the late 60s.



Hate to disagree, but the 427 made more torque than the 428 at the same RPM, 476lb/ft@3400 for a single 4v vs. 440@3400 for the CJ