Hi Tom. Welcome to the 'bolt.
There are a few folk on this site who have done a chassis swap,using a later set-up from a junk yard.
There are companys who build aftermarket chassis but obviously there's a cost! $$$$$$!
Sit tight and some one will chime in soon!
There are plenty of alternatives to swapping out the chassis,but it's entirely up to you
and your wallet.
Jock
