B Bodies & 340’s

[Moparfiend]

I would like to know some specifics regarding the automatic drivetrain combinations used in say Roadrunners with 340’s.

What rear end and torque converters (stall specs) were used along with engine compression ratios and camshafts specs if possible.

Thanks MF

 

[R413]

First year for a road runner with a 340 was 1971. Because the
340 is down on torque with 340 ft lbs compared to a 383 with 425 ft lbs of torque.
And 340 is down on horsepower with 275 compared to a road runner 383 at 335 horsepower. A 1966-1970 b-body is a heavy car, that's why the factory didn't put a 340 in them.
340 was an A body only engine in 1968-69, and really make a good combination.

1971 road runners were smaller and lighter cars by about 300 lbs depending where you get the numbers. Better aerodynamics also.

 

[Moparfiend]

See my update below

 

[Moparfiend]

If I’m not mistaken, the 1970 was rated approximately 200lbs lighter than the 1971. But 3/10 sec. in a quarter mile isn’t a big deal either, but let’s not go there because this is not what I was asking for.
I am however, asking about the set ups. Anybody out there with a 71 to 73 roadrunner with a 340 in it that wants to comment about their configuration?

 

[Bighouse]

I’ve got a 69 Charger with a 340/727. The casting date is late 69 on the block. I bought it like this. The only thing I know about it is it has a crane rocker set-up and some lumpy cam, an edelbrock manifold and carb, HEI distributor and headers. It’s faster than I thought it was going to be.

It had 3:55’s that I swapped for 3.23’s for a little more highway.

Don’t know if that helps, but I like it.