Hey all.

First time rebuilding an engine and I am doing it on an extremely tight budget. Years ago I purchased a 66 Coronet body and a 426 street wedge from a yard and just now have the garage to work on them. I’m focusing on getting the engine running, not for drag or top performance, just running to ride/play with. The engine was purchased dis-assembled with most of the major parts included (block, heads, intake and exhaust manifold, old Holley carb, crank, cams, pistons, timing chain, old distributor...). I’m in the process of cleaning the engine and checking for cracks/wear&tear and am not planning on getting anything milled/honed/bored. I will be getting new gaskets and all new bolts to be on the safe side. Looking over the pistons I noticed two of them are cracked with chunks of metal missing between the piston rings and are surely not usable.

So my question is, can I purchase only two stand alone pistons to match the set I already have and if so, where do I look? I know purchasing a whole new set of pistons is pricey and a mis-matched set can throw everything off from balance to head spacing. All the connecting rods and bearings appear to be good. The cast number on the piston reads “2465533”. Cast number on the block is "2532230" and the cast number on the head is "2843906".

Thanks in advance.

You have to take precision measurements of the bores before you do anything. They need to be measured to the .001" in the top, bottom, and middle. Each bore must be the same front to back and side to side. That's the only way to know if the holes are really round.

Chances are good that you will have slightly oval shaped holes and a ridge around the top.

Only after you have confirmed the bore measurements can you order pistons.

426W pistons are neither cheap nor readily available. Dig around and find prices and part numbers. Be sure to punch the numbers into Amazon to check for better prices.


I'm doing the same thing for my Imperial. Luckily, it has a 440 and the pistons are readily available.

What you have is going to cost way too much to get running. 426 wedge parts are worth money. I would recommend selling what you have for enough money to buy a running 440.

That engine you have is using 906 heads , open chamber , the small bore of the 426 wedge is hard enough to build compression with , now you have even lower compression with those open chamber heads and your deep in the hole pistons . A 383 piston is probably fairly close to the CH of the stock 426 piston.

Ill run the micrometer through the cylinder. If they only have a ridge then I can ream it out but I would still be left with the problem of finding two replacement pistons.

So the best thing to do would be bore and hone the cylinders and drop in a "new" set of pistons? Maybe 440 pistons?

the stock bore 440 4.32" pistons might work, only a 0.070" overbore?

Is this for a stock bore 426 wedge? Flat top pistons? If so I have a set of 8 pistons # 2406395 that came out of a standard bore 1964 426 wedge.

As far as I am aware the engine is a stock 426 wedge with a standard bore. Only has 426 stamped on top of the block, no other letters or number stamped. And has a cast date of 9-15-64 along with the block cast number. The piston is a flat top. But my cast number on the piston reads different than yours.

If I choose to machine the block, how much larger of a piston can I drop in?

What factors to I have to take into account if I upgrade the pistons? Do I need to get a new crank, etc...?

You need to have the block sonic checked before you even consider trying to overbore it large enough to fit a 440 piston.

What is the goal of this engine ? I don't know if you said that , I didn't go back to reread your original post.

Your questions reveal some basic misconceptions. Pistons do not "drop in."

New pistons and block go to the machinist so the bores can be sized to the pistons. If you are not sure what size, get the block to the machinist first to get the necessary oversize figured out.

Next, boring to increase engine size is not profitable in Mopar engines, because casting quality (core shift) varied substantially in all the years. More to the point, a sonic check is very much what should come first to see what cylinder walls your block has. Boring the 426 to 440 size is something I'd never recommend.

The corollary to this is that stroking a B/RB is so easy and can be done for large displacement increases.

Now on to the bores. If there is a ridge there is almost certainly wear in the bores. Reaming the ridge is a very hazardous operation for the novice. It is just too easy to cut too deeply into the cylinder to the area where rings need to seat. The area of greatest wear in the cylinder is where the rings are loaded the highest, at the upper end of the cylinder.

If you want to keep the standard bore and not mess with the cylinders then the used set mentioned above is a good choice.

Imho you'd be best off having a new set of pistons made by Autotec. Then they can have the compression height, valve notches, any dome, etc exactly to optimum.

R.

Yea, Im trying to find the best bang for my buck in local machine shops to do the sonic, machine and honing.

I want to keep the engine stock as much as possible for cruising. But if I have to replace the pistons b/c I have have two broken ones then I mind as well upgrade the displacement for street. Not looking for bracket, drag or any peak high octane performance. Street performance is sufficient.

Now that I read your original post ...

You need to measure your bores for taper and roundness before you can sensibly move forward.

Mopar made three different 426 Wedge motors in 1964, a 365 HP street wedge,(came with flat top cast pistons) a 415 HP Max Wedge and a 445 HP Max Wedge that came with domed forged pistons. They stop making the the 426 M.W. motors in either late February or early March and started putting the 426 Race Hemi motors in the last Dodge and Plymouth they had firm orders on for the M.W. motors. My point is you do not want to use the forged high compression pistons in a used block with a ridge on the top of the cylinders. They offered the street wedge in both 1964 and 1965 and stop making the 426 wedge blocks for passenger cars after the end of production run in 1965. They alledgly made a 426W race block later for NASCAR application, never confirmed one way or the other by Mopar
I had a 1965 street wedge block bored to 4.320(stock 440 bore size) as it was bored to 4.310 already and had some taper in the cylinders, that motor ended up with a 4.25 stroke crankshaft and a set of Eagle 7.100 long forged H beam steel rods with a set of custom Ross piston to lower the compression down to 9.5 to 1 to run California pump gas with iron heads back in 2001 or so It ran fine on pump gas and made close to 500 HP on the DTS engine dyno in Ontario, CA ran by Vrbancic Bros.
I didn't want to build that motor as it had two external freeze cracks in it and a casting flaw in the bottom of # 4 cylinder that had been seeping water into the crankcase since day one The customer insisted on fixing and using it as he had a 1965 Plymouth Satelite 426 street wedge motor car and that block casting date was proper for his cars scheduled production date
As already mentioned your bare block may be worth more than a complete decent running 440 to a restorer or restoration shop
Good luck on your project, keep us informed on what you do please

The bore size means nothing to build power on a street engine. Standard bore is fine. Those 906 heads will kill all your power, get some closed chamber heads and the 516's would be fine for a street car.

Up until Monday afternoon, I had a 1964 HP stamped 413 engine on a stand in my shop. It appeared to be a 52 year old virgin. It had 516 heads on it, the block did not appear to be cracked in the valley and it turned over easily. It had been left on an engine stand in a corner of the shop 2 years ago by the son of the previous homeowner. One of my neighbors called and wanted it for a Duster drag project he has started. So I called the owner of the engine, he said he would not come up from California to reclaim it and therefore it was mine. I already have a Cab Burge built 440 race engine and a backup '77 440 truck block, so the only reason I would want it was for the steel crank. So I gave it to my neighbor, stand and all.

Find yourself a running 440 to build from a truck or motorhome and leave the 426 to someone that needs a block to build for a class racer.

Yeah.. sell it and get a 440. Pistons are gonna be the big problem (aside from custom).

One thing to keep in mind is that the 426 bore size is 4.250 stock, the 440 are 4.320, .070 bigger than the 426 bore, that is only .035 per side How thick do you think the ring ridge is? Maybe boring that block to 440 stock size and buying a set of stock 440 bore 6 pak pistons to use with your 906 heads may be a viable option to build a nice relaible street cruiser that will still put a smile on your face when you floor it After all, there are some things a man can never have to much of, fun, money, traction and horse power

Another thing that nobody brought up that might be a problem. You have 2 pistons that have broken ring lands, broken ring lands are caused by detnation. It would be surprising that only 2 pistons were affected. Without a magnaflux crack check your other pistons also could be junk. And on the overbore to .070 over? Your money but I wouldn't do it. Sell your good block for enough money to buy a rebuilt 440.

Did the older model 440's that were put in trucks/RV's have any performance? Are they different from the 440's that were put into performance cars of the same era? Im sure that all 440's didnt perform the same.

Will a 440 fit into the engine compartment of a 66 Dodge Coronet?

They're the same as their similar year passenger car counterparts. Any 440 72 and later is going to have low compression, 8:1 ish. They used the same heads as the cars did. I have a 77 440 in my 67 Coronet that was stock except for headers and it had decent power. I'm putting a cam in (Summitt 6401), Holley Street Dominator intake, and an Edlebrock 800 Thunder Series (same style as a Carter AVS).

Yes, a 440 will fit into a 66 Coronet

The later modle motorhome and pickups 440 motors where designed to tow, they are not anywhere near a pre 1971 hi po 375 HP 440 magnum motor
As far as fitting one of those motors in a 1966 Didge Coronet I'm doing a install now on a original 1966 Dodge Deluxe two door sedan six cylinder 3 speed stick shift car, I pulled the six cylinder K member out of it today and will put the V8 K member in it tomorrow. It will end up with 440 block stroked to 3.91 with a 4.35 bore size and a set of Herb McCandless hog out 452 iron heads and a Eddy RPM Performer intake manifold with a Holley 850 D.P. carb. on it. Nothing exotic, I did have a 4 speed hump put in it so I can use a NP833 O.D. tranny out of later model pickup or van. I bought the steel 1966 to 1972 BB engine mounts and rubber mounts from a local racer that had a set for sale so it will bolt into the 1968 B body V8 K member I bought from another local Mopar guy. I hope to have it running by the end of this summer
I had it painted last year and the interior done this past winter, nothing ever goes as planned
I was planning on having it running last summer Good luck on yours

I do like the idea of stroking a 440 out down the road; since time and money are restricting me atm. So if I want to go the route of 440 engine, where should I look and what should I look for? Pulling a 440/6pak out of a magic hat will be expensive, Im sure. So what other 440 can I drop into the Coronet that will still get me a little power now and be able to give a performance upgraded at a later time? I dont want to get an engine now and it turns out I got the wrong one and am stuck with a 150hp paperweight.

Any 440 will fit , the chances of finding a performance model that needs to be cleaned up and dropped in are pretty slim . unless it comes wit ha warranty you need to treat any used engine you buy as a CORE ...

What is your budget ?

Like I posted earlier, any 70's 440 (truck,car,motorhome or otherwise) will be fine. With a cam intake and headers 350 hp is easy and it'll still be driveable, don't get hung up on the "high compression" late 60's/early 70's 440's. Did they have better compression? For sure but it was no where near advertised (except 440 6packs, they had a better piston). Any 70's 440 is essentially the same. Were there differences, sure, but it's mostly in things you'd change anyway (cam/valve springs). They all used the same heads, same intakes and the same blocks/Pistons. Plenty of guys on here have used low compression 440's pulled out of New Yorkers, trucks, motor homes etc and made decent performers out of them

R.

Plus that block does have restorer value.

Been talking around town and might have found a mid-70's running 440 with trans from a guy. He said it runs dry, not sure what that means. I dont remember how many miles he said were on it though. He is also gonna keep an eye out for anyone who wants to buy the 426.

If the engine and trans came out of a truck or RV, is there anything I should worry about with putting into the car? I read somewhere that the truck transmissions cant/shouldnt be used in cars. Cant remember the reason why though. The Coronet Im putting the engine in has stock/original axles and driveshaft.

Some of the larger trucks and motorhome chassis with BB motors had the emergency brake on the trans, not on the rear wheels. As long as the tranny your getting has the long output shaft, not the short one with the emergency brake on the tailshaft, and the standard type slip in trany yoke and Ujoint you should be fine Some of the cars and trucks had a two piece driveshaft that the front Ujoint bolted to a fix tranny output yoke Any of these trannys can be converted to passenger car use as long as you have the parts needed to convert them