72 340 build vs...other options

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Dartswinger70 said:
Thanks for that info. Very well presented / Let me run this by you. say someone picked up a standard bore 72 340 with a forged crank and flat tops. couldn't they switch the cam and pistons and in effect have an early high comp 340?
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Yes indeed ask but he cams are the same.
Dartswinger70 said:
In my mind I cant see why not but I ay be missing something. I think my point is a later 340 is worth something in parts although Id stay away from the external balance but that's not a show stopper either.
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True if your swapping parts from one 340 to another 340.
Which does t make sense, but yes, it’ll work and be the same as the other one.

Any low compression e home just needs pistons to fix the problem. Or a heavy head milling. Off set stroke to the crank, but that’s really crazy to do unless you can do it yourself.

IMO, this is where a 360 comes in nicely. Refit it with higher compression pistons and your off and running. The rest of the engine can use the 340 parts very well.

I wonder what that would dyno at?
 
My take.
340's are cool nostalgia, If I had an all original 340 equipped car, yes I'm keeping it. If I happen to have a 340 around by itself I'll sell it to someone who'll do more with it than me whether it's a restoration or is really big into nostalgia.
360's especially 5.9's you can "do more with less" so to speak. Or go with the gusto: 408 stroker based on a roller LA 360 or 5.9 magnum.
Like I said, I like 340's, my favorites are the roller LA 360 and the 5.9 Magnums.
And 318's are not my most favorite but will still run them as I think they are great general purpose motors, I have a lukewarm disposition about them.
I only owned one 318, was a real good motor, gave me little to no problems just had a ton of miles when I picked up the truck I used to have (est. 290,000+ miles). Until I replaced it with a low mile 360 from a wrecked 1991 Ramcharger as it was starting to burn oil and had really bad blowby. Still pretty good considering that 318 had a hard life.
 
I like the 340... but I admit I am biased, since I have one under the hood of my Duster. It's stroked to
418" inches. 10.1 comp. Uses the factory J heads that have stainless steel 2.02/1.88 valves. Heads are ported.
This is the first 340 I have owned. I have had a couple 360's but those were trucks that were completely stock. It makes good power (seat of the pants).. engine has never been dyno'd though. It was was built for street -strip duty, with a solid cam, and single plane intake. Looking to sell possibly.. if anyone is interested, PM me.

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Realistically if cost and availability wasn't an issue block wise sbm 340, bbm 400/440 (depending on stroke), anything smaller is a compromise, especially sbm since every bbm has an even bigger bore.
 
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