big block caddy or slant six mopar??

I would have to say use the cataract...
They make a pretty engine with all the erroneous **** scabbed off of them.
I dressed one up a few years baks and it looked really nice (still does,the heads dont boil the paint the way other motors do)
then there is the "BIG WHOMPIN POWER!!!!!" aspect to it.
I used a bulldog intake and cam and that motor sounded absolutley terrifying. it would also lay patch for a city block in a 1967 caddy 4-door.

my point is, it's an awful lot of motor. lighter than a big block, dimensionally the same a a small block. if your s.b.c. scares you, then just throw some chrome at the caddy and you're are set for all events. They make good power on stock parts, so you save a ton in buying only what is needed to make it look right.
or put it under a hood and go nuckin'futs.

 

well, i was thinking about this, the caddy would be cool for just shear cubic inches. but the 6 banger has some potential, you could recess the back of it into the fire wall, that would visually keep the over all length of the engine bay the same. The engine has a nice tall stance that would keep the carbs up in the air (3 dueces on a log would look trad), primerdust318 has a great after market triple 2" SU set up on an original aftermarket intake that would really set your engine apart. Mill the head a bit to get some extra compression and split the headers and run in on straight pipes (or something to give it a great cracking sounds) there are lots of go faster goodies out there for the slant six, and you could dress it up and even make it a looker.