'62 B body with the flat pedestal motor mounts. Are they like the '63 and up where there are two different K members for the small block and big block or will the '62 K member accommodate both?

I like to swap those early K members to the later 1966 to 1971 B body V8 K members, preferably to the 1968 to 1971 with the better idler arms.
That moves the motors back around 1.5 to 2.0 inches and down a little which helps make the weight distribution better as well as carb air cleaner to hood clearances a little better as well as header choices better

I was hoping you would see this post Cab.

The newer K member may be in the future.

Short term, can I put a big block in a '62 that came with a small block or are the K members different?

All V-8’s except Hemi will fit on the same k-frame. There was an early for 62 k-frame that used a can mount - not sure if that applies to them.

Bottom picture shows a 1965 V8 K frame if this helps. Top picture is a 1970-71 B body K frame which moves the engine back an inch or so. Both of these K frame are for sale in the classifieds if you're interested in either one.

Thanks!

I've never compared early to late side-by-side, and can't recall seeing that excellent photo comparison before - thanks for posting that.

I'm struck by the width difference in the engine mounting pads/bases.

IIRC, the engine setback difference from early B to later B K-members is about 1.5"
Buddy of mine who did that swap on an early B said it played hell with the right-side Maxie exhaust manifold at the firewall.
The setback sure seems advisable for some builds, if you're sure the headers/manifolds don't hit the firewall.

The '62 K-member is a one-year-only. V8 works with both SB and BB.

I liked those 62 mounts if you can still get them. Try using the later k-frame with a Max x-ram, real close to firewall with stock k.

Plastic mallet on the firewall as needed to help improve on the road performance on M.W. motors with later K members

Schumacher has the lower brackets, the block brackets and insulators are the same '62-'65.

https://www.engine-swaps.com/products/62-b-body-b-rb-adaptor-brackets

I first bought a 62 Dodge 2 door sedan with the max engine in it. Ugly car racing till I found my 64. I used same mounts off the 64 383 for 426. Later on still having those 62 mounts I decided to put a 383 Super Bee engine in my CJ5, only thing needed was those mounts and 4”x4” 1-4” angle iron bolted to frame. I used a 64 3 speed bell (borg) to mate to the T-85 Borg Warner trans, changed clutch disc to match. Only one hole was off a little so drilled and tapped that one. That CJ5 would SCOOT thru the woods and hills. Sold it to a young kid and he flipped it 8 times, tore it all to heck.

If you move the motor back you'll need to do some additional work, shorten the driveshaft, different trans mount, modify exhaust. Unless you're racing I'm not sure the additional work results in any real benefit.

I used the stock '63 K in our '63 330 and I'm glad we did. I need all the help I can get to keep the front end down!

You can elongate the trans mount holes or swap the tranny crossmember to the 1966 to 1971 B body style
I recommend sliding the motor back and converting the 1962 to 1964 trans to the 1965 727 tail shaft housing and output shafts you can convert to the later, better and stronger front drive shaft yokes and do away with the OEM ball and trunnion U joints

A list of the benefits?:

Moving the engine back was good when it had no HP

Increased fan/radiator clearance is the main benefit to me. The actual measured setback is 1 5/8".

More choices on headers is one, #6 spark plug to the fender well clearance, increased air cleaner to hood clearances is another and less weight on the front tires is another, better oil pan choices and so on
Cudaman, Speaking of HP, how fast have you gone so far?
My quickest run so far at 2860 lbs. was 8.86 at 150.+ MPH in the 1/4 mile, 5.50 at 125. MPH in the 1/8 mile at the same weight in the same car. with a single four barrel using pump E85 How about you
I'm shooting for mid to low 4 in the 1/8 mile at 170+ MPH in my new heads up no prep car, maybe quicker and faster

in years [long] past, i beat severely ball & trunion u-joints, with and without good traction, and they held up quite well, as good as the later style 7290 joints.
the only real problem was with the rubber boot cracking or tearing, then spinning out the grease.
they are not the easiest joint to replace, and when one does this, you need to be very precise. the FSM shows how to do it.
then you need to have a good tool to crimp the boot retaining straps on. [think tool used for front drive axle boots]
the 65 and later slip yoke joint solved the issue of difficulty [and time factor involved] in replacing front u-joints.