The non-integrated manifolds ran longer than '74. My 250 engine is from about '76, separate manifold. I've seen a few even later than that - they seemed to be using up old stock here and there. Best bet is eBay or your local wrecking yards.

The best use for that integrated manifold POS is a boat anchor.


Get a REAL truck, get a GMC! www.oldgmctrucks.com
1954 GMC De Luxe COE