I have been working on my 68 barracuda for a couple of years so I'm definitely no expert. But from what I have learned, there is a difference between a 6/small block k member and big block k member and a hemi k member. I know you can use Schumacher conversion mounts to convert from a small block to a big block. I'm switching from small block to big block myself and have'nt decided on useing a stock "big block" k member or the tubular one. I don't want to use conversion mounts on mine... in my opinion..a tubular k member would be better but I want mine to be closer to original . There are a lot of great guys (and women) on here who are Mopar well springs of information, so your in the right place. You might also read some of the other forums if you haven't already. This is a great place for information, finding parts and meeting good people.
