The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - BBC in 67-72 4x4

midyearvet@aol. · 07-12-2003, 07:20 PM

I have a 427 in my 72 stepside 4x4. I bought the truck new & put the BB in it in 1976. Dimple firewall slightly around clutch rod hole & use corvette power brake valve cover on left side. Everything else fits. Used corvette exhaust manifolds-had to modify xmember under engine for clearance & then gusset on under side for strength. Used all 2 1/2 exhaust pipe, but started breaking hangers. Ended up with 90 out of manifolds 18" of flex pipe & then mounted rest of exhaust ridged to frame. Every 2 years you will have to replace flex pipe, but works great. Only problem since is breaking front axles. They wern't ment for 390HP!
Good luck Rick-Ca.

07-12-2003, 07:20 PM	#18
midyearvet@aol. Registered User Join Date: Jun 2003 Location: Napa, Ca. Posts: 103	I have a 427 in my 72 stepside 4x4. I bought the truck new & put the BB in it in 1976. Dimple firewall slightly around clutch rod hole & use corvette power brake valve cover on left side. Everything else fits. Used corvette exhaust manifolds-had to modify xmember under engine for clearance & then gusset on under side for strength. Used all 2 1/2 exhaust pipe, but started breaking hangers. Ended up with 90 out of manifolds 18" of flex pipe & then mounted rest of exhaust ridged to frame. Every 2 years you will have to replace flex pipe, but works great. Only problem since is breaking front axles. They wern't ment for 390HP! Good luck Rick-Ca.