[GoneNova/406]

this is probably a question for seasoned mopar nuts or machinist thats been around awhile.some yrs. ago i was going to start a project on a 1970 swept line camper special dodge pick-up 3/4 ton sraight axle.i had a 360 to build and decided i needed a bigger engine and bought a 413 out of a 1971 superior motorhome.the old guy i got it from wanted a little more power and bought a 440.anyway,i read in the mopar performance book 8 th edition that you can safely bore the r/b big blocks .060".since it shares the same block with the 426,can it be bored to 4.24 or 4.31 asumming that the bore was the stock 4.18 to begin with.the block # is 2658836 industrial with a steel crank and the date code is 7-14-70.some of the different parts come back as wedge and 440 six pack parts.the only 426 block being made at that time was the dual 4 hemi.i was wondering if thats the block that they start with also.

 

[spinn]

a 440 has a 4.32" bore. a RB block should be able to be taken to that bore.

i think that the M block was the hemi's. so is the casting # preceeded by a M?

 

[GoneNova/406]

no.just the 2658836,and the book says its a 426 industrial motor.the old guy i bought it from told me it was a 413 and the cylinders measure to a 413.but the # comes back as 426 industrial.i know they share the same block.sounds to me like its a 426 that only got bored to 413.and the hemi head motor would have the m,but what if they just used the block as special order and not the head.in the book it was the only 426 being made at the time,64-71.the 400 motor is #3614230 71-72,but its a B block.max wedge is 64-66.you could go with the idea that it was just an earlier 426 but the block # corrallates (7-14-70)with the hemi motor 64-71.

 

[Garbonzo Bojangles]

I believe all 426 hemis have cross bolted main caps. Does yours? A hemi block is friggin huge, too.

 

[Stickman]

It's probably a 426 wedge. There weren't that many built, but they did build 'em. Not sure how many 'truck engine" 426's were built, but my guess is, you've got one. Not a "Max Wedge", I don't imagine (they were built only in '63 and '64, I believe), but a nice, big Mopar, none-the-less. The heads and water pump may be quite a bit different from factory stuff for car engines...I know I got a 413 from a motor home once, and it was that way also. Huge water pump, actually bolted to the heads and block both.

But the block, for all intents and purposes, is the same as the 440 block just with a different bore, though the cylinder walls may (or may not) be slightly thicker..can't say. Even so, I don't think you'd be able to take it all the way out to the same bore as a 440. That's a very long way. If you want more cubic inches, use a stroker crank. That's the easiest way to do it without over-boring your block (you can always take away, but you can never really put it back). It's a bit more expensive, but your block will remain intact, provided you don't get wild with the throttle.

Also, Garbanzo Bojangles...aside from being cross-bolted on the mains, there isn't that much difference between a Hemi block and a Wedge block, at least not to the naked eye. What made it look so big was the heads. They truly were "friggin' Huge".

As an aside, here..I just read that On July 4, 1971, four cars with 426 cubic inch versions of the 440 with ported 440 heads were entered in the Daytona Grand National race, and they finished 1-2-3-4.


[EDIT]

You know, the more I think about it, the more I think that the guy above is right, and you probably can take it out to 4.32 (440 bore), but I don't think you should, really. That doesn't leave you any room later on, and you'll have to use sleeves.

 

[GoneNova/406]

thanks guys for your help with my mopar questions.i thought i read a couple of yrs. ago in one of the mopar books i've got that you can bore the 426 out to a 440 but looking at the 8 th edition mopar performance race book it says .060".thats not important to me though,i just like to know as much about the parts that i'm building with as i can.i know about 413 motor home engines but i would think that the casting #'s on the would come back as 413's.i keep getting the i dea that this block is a little out of place here.i found a mopar site a few yrs. ago that had the best info i've been able to came up with so far but some how lost track of it.i've got about 500 different mopar sites through links and just can't quite nail it down yet.i do have some info from an article in hot rod a few yrs. ago that described the 413/426.it was quite indept and told about a dump truck motor,pick-up motor,wedge and pass. and i am all but sure that this is a wedge block and not the run of the mill motor home 413 but i won't be happy til i know all about it.its hard to build a motor til you know what you're building with or to sell it which at this point is what i'd like to do to be able to put the finishing touches on my 406 sbc.thinking about putting it on the bullitin board at jegs.i wish i was able to put it to better use.the possibilities with a 426 are endless.well thanks for the help anyway guys.