So you want 2 go Big block...Read this first!

corect me if I am wrong I don't know the guts of engines verywell. a 440 motor home motor has a cast crank, and it is better to have a forged ( or is it the other way around) 340's have a better crank and a better platform to start with. 440 motor home is a smogger, where a 340 is a HP motor. 340 are high winding, where a 440 motor home one isn't.

I am pulling at strings on this one, but that is what I have heard, and think.

Phil

if you guys are comparing a 340 to a 440 which would you buy... a complete 440 for $500, or a complete 340 for $500? both may or may not run.

ok. motor home i would thing could have either cast or steel crank depending on year.

340 can also have either crank depending on year.

a cast crank is fine depending what you want to do wit it. i believe its limits are in the 500-600hp range. so anything up to that is fine. my 440 that was in my valiant and demon had a cast crank. car ran mid 12's on street tires and probably could have dipped into the 11's with traction and more tuning. was street driven and got the living **** beat out of it and that cast crank was just fine. problem is people tend to take what the magazines say as gospil and bad mouth the cast cranks, but in realality they are fine up to that point. plus the cast cranks came out at the same time the compression ratios dropped for emmissions so they get a bad wrap for that too.

as far as the smogger part of it goes. the blocks are all the same. 68 i think it is has a little more nickle in it and later years are said to be thinner walled but the blocks are pretty much the same. a smogger 440 can be built the same as a HP 440. different years had different head castings. in the past because the magazines said the 906 heads were best everyone had to have them. now the 346 and 452 heads are better to hog out. plus the later heads have hardened seats wich are good.

between a running 340 and a running 440 for $500. i would buy the 340 and sell it to some idiot numbers guy that wants it for a nice profit and then go buy the 440 and have money left over to put parts into the 440.. :)