Road Runner Nest

Are the early 70's 413 motorhome motors the good ones with extra webbing and better cooling. Are these able to be bored 60 and be reliable? Does everything bolt up the same as a 440 in a car like power steering, a/c, ect. Thanks.

I'd like to know that too. I've heard the later ones have thinner cylinder walls, making it risky to bore them over. I had an opportunity to buy an unmolested 76 engine recently for 300 smackers and turned it down. I keep wondering if I should have bought it.

My mopar book tells me that the 413 engine only came out in 60-63,after that it was a 440. It also states that the 1976-77-78 blocks for the 400 and 440 are a thinwall casting design,as such they shouldn't be overbored more than.020".

Sorry, I was being an airhead after a long day. I was looking at a 440.

the pass 413 rb 1959- 1965 the 440 1966 - 1978

FWIW....

My father has been rebuilding engines for a living for over 40 years, and for the last 4 years or so has built pretty much exclusively Mopar power plants.

I can tell you for a fact that you will not have a problem boring a later model 400 or 440 to at least .040. As a matter of fact, the block in my runner is a 76 era truck block bored .040.

I have heard him say that .060 over can occasionally cause some heating problems at times due to the thinner castings. That said you rarely have to take a big block Mopar to that oversize unless it was bored previously or maybe really abused.

Just my 2 cents!

Thin wall blocks? I find the information on this site to be a very interesting read on this subject.

http://www.440source.com/blockinfo.htm

Great info, I got my info from the mopar performance book, Most of the info was from mopar enngineers. Thats why they dont want you to bore more than 20 over.it makes sense.thanks 72RoadRunnerGTX. Thats why we are here to learn from each other

So...is a 413 more closely related to a 383/400 or 440? Or 426? Were the heads any good?

The 413 was closer to the 440,it was a wedge motor.and was also an rb engine,the 383-400 were b engines.

hi there they are all wedge motors

LB 350 361 383 400

rb 413 426 440 426 hemi Block
and a 383 rb one year only 345 hp 2 4bbl




Block Bore Stroke CID Block Bore Stroke CID
4.06 3.38 350 4.18" 3.75" 413
4.12" 3.38" 361 4.25" 3.75" 426
4.25" 3.38" 383 4.32" 3.75" 440
4.34" 3.38" 400 4.03 3.75 383 this one

Exactly, all but the hemi were wedge,but the hemi was an RB like the 413 and 440. what year was the 383 an rb? I forgot that there was also a 426 wedge also.

They stopped putting the 413 in cars in the 60's but they still had them in trucks, motorhomes and industrial use, If I'm not mistaken the motorhome blocks have extra webbing inside the crankcase and larger cooling passages in the heads. They also had sodium filled exhaust valves. I cant remember what head was used in them. They were used well into the later 70's. I didnt know what years were the better 413's but after reading up on things at 440 source.com I got the info I needed. Sure was some good reading there.