Selling my 1971 Demon. It has a 1971 360. In the add I mentioned manufacture year of the engine but that's it. Should I give more notoriety to the engine because it is a first year 360? I realize a sonic check is the only factual way to verify the amount of meat in a block. Trying to do a well informed factual write up on my car.

I'd think if the engine was original to the car that would be sufficient...

If the engine is not a numbers matching block then I would just list it as a date code correct block...

I don't think any potential buyer is going to care about the whole sonic test...thickest block...blah blah blah information.

Is it original or not and will it replace original or not...

The general public doesn't even grasp all of the intricacies the faithful have found...

I was told at one of the old Mopar drag seminars that a lot, some, of the 1971 360 blocks where made from 340 castings so they where thicker on the water passages around the bores than the later blocks made after the early 360 castings
I would not try to embellish this information to add to the hype on selling the car
Let the car sell itself
You do know that 360 motors where never offer in A body until 1974. correct
They were installed in C bodies only in 1971

HOOBOY, ain't that the truth ! [in more ways than one..........]

Is it standard bore?

Cab remarked "You do know that 360 motors where never offer in A body until 1974. correct scope
They were installed in C bodies only in 1971 shruggy"


Cab you do know that I NEVER CLAIMED THE 360 WAS ORIGINAL TO MY CAR???

I dont know. Bought the car as my project in 2002 non running. Life then happened over and over and now in 2020 my back will not tolerate the needs of my beloved mopar.

So far Ive not gotten alot of interest but several respondents don't know what a reverse manual valve body is. FYI This car was originally a 6 cyl car white with black vinyl top. Some dont understand the benefits of the larger wheel bolt pattern conversion either.

Do you know that the second post in this thread seems to think a 360 might be original to the car?

That's probably who Cab was thinking about.

Nothing real special about a 71 360.

From one of my old Mopar Performance "Engines" books.

.

Early 360s, 71~74 - 3418496 - were done with 340 water jacketing and can be bored as if they are a 340. We always did them to 4.030 or .060. 4.060 is like a .020 over 340.
Later 360s - 3810230 4179930 - were 360 castings with thinner cylinder walls.

This is information I've found over the years and never confirmed myself with a sonic tester. Checking wall thickness is always recommended.

Really only useful for someone looking to race the thing, build a stroker or go for a bore larger than 4.070. If a potential buyer doesn't know what a manual valve body is, I doubt he would be impressed with the block being an early piece with thicker cylinder walls.

Well, I'd say there really isn't anything there for you to add. If it is the thicker wall block like being discussed, and maybe 40 or 60 over, it's worse than a later standard bore thin wall.

I think it's best just to leave it as is and let the Buyers ask the questions. If the car is smoking and yours isn't re-buildable, they can pick up a standard 360 from practically anywhere for $100. It's not the end of the world, all old cars have their issues.

I would have stated to you in that post to not try to sell it as a original 1971 360 A body if I thought you were trying to pass it off as OEM.
I wasn't sure if what you knew about Mopars and the 360 and 400 motors that were produce as smog motors in the early 1970s

Just put its got an early #6 360 block. Anyone who knows anything knows what that is.

Thanks everyone.

Good thread two bolts.


Back in the day someone spread a malicious rumour about thin wall 440 blocks!
Think it was actually in the ‘holy bible of Mopar’ Mopar engines?
But thanks to ‘Brandon at 440 Sauce’ this myth was finally dispelled.


So back to 360 blocks and the new myth of 340 sleeves in the early casting?
Surely someone in Moparland has sonic tested one or two by now...
They is 50 years old in a few weeks time, so why hasn't it been busted yet???
Good program that, one of my favourites when stuck in a motel in Vegas with nowt to do... Myth busting”


Ps, core shift is a bigger worry in any block anyways...

Going by memory here- In the 2000s an engine build shootout was done. Representing the mopar camp was the legendary Dick Landy. He used what folklore said was the weakest era RB 440 block for his build. He beat the Ford and Chevy camps and won the shootout with spectacular results. As far as my car for sale I have listed every positive and neg verified with pics and listed the decoded VIN and fender tag to avoid any misrepresentation.

Got one of the early blocks .070 over.....

Ran it for over 10 years as a .060.....

Last time out in Bakersfield with Speedmaster heads it ran 10.46 @ 125.13....

Nothing special...MP590 cam cause I had it...

I have a 408 30 over stroker coming together with a later block, what might I have to deal with? street only.