77 Dual Exhaust

mich77442 · May 17th, 2007, 07:28 AM

I need some help. I am new to the A-body cars and to Olds. I have a 77 442, I what to put dual exhaust on it to make it sound better and run better. I have found out that I need a cross over to make this car a true dual exhaust. Is that true? If so where could I find one.

Thanks
Denny

Oldsmaniac · May 17th, 2007, 07:59 AM

Actually I think you need a cross member....1974 cars and down had provisions in the cross member for an exhaust pipe to run on either side for dual exhaust. The cross member is the brace that the transmission tail is supported by. Without the older style cross member the pipes cant be run easily for duals because it is only designed for a single pipe on one side only. Ya may try junkyards, online sources or Ebay for a Cutlass cross member from 74 or earlier.

joe_padavano · May 17th, 2007, 09:28 AM

Quote:

Originally Posted by Oldsmaniac

Actually I think you need a cross member....1974 cars and down had provisions in the cross member for an exhaust pipe to run on either side for dual exhaust. The cross member is the brace that the transmission tail is supported by. Without the older style cross member the pipes cant be run easily for duals because it is only designed for a single pipe on one side only. Ya may try junkyards, online sources or Ebay for a Cutlass cross member from 74 or earlier.

Actually, I think only 73-74 A-body crossmembers will work. The A-body is any Cutlass, Chevelle, Grand Prix, Monte Carlo, Regal, or Century from those years. I'm not sure if GM kept the double hump crossmembers in 75-77 or not. Doesn't really make sense for them to change tooling until the model change in 78. You may want to just look under the car and see if your current transmission crossmember has one hump or two to clear the exhaust pipes before you buy anything.

Oldsmaniac · May 17th, 2007, 11:22 AM

I have some experience with this as I put a 455 in a 77 442 and installed dual exhaust. Im pretty sure the single hump cross member came about in 1975 when the only option was a catalytic converter and single exhaust. I used a cross member from an earlier car of which vintage or model I am not sure of but am pretty sure in was a Cutlass. The only problem was that the tranny mount was a single bolt mount and the older cross member was drilled for 2 bolt mount. I simply had to drill a new hole for the trans mount in the old cross member and possible some new holes on each end where the cross member bolts to the frame of the car....It was no big deal.

May 17th, 2007, 07:28 AM	#1 (permalink)
mich77442 Junior Member Join Date: Mar 2007 Posts: 8	77 Dual Exhaust I need some help. I am new to the A-body cars and to Olds. I have a 77 442, I what to put dual exhaust on it to make it sound better and run better. I have found out that I need a cross over to make this car a true dual exhaust. Is that true? If so where could I find one. Thanks Denny

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May 17th, 2007, 07:59 AM	#2 (permalink)
Oldsmaniac Registered User Join Date: Oct 2005 Location: NJ Posts: 702	Actually I think you need a cross member....1974 cars and down had provisions in the cross member for an exhaust pipe to run on either side for dual exhaust. The cross member is the brace that the transmission tail is supported by. Without the older style cross member the pipes cant be run easily for duals because it is only designed for a single pipe on one side only. Ya may try junkyards, online sources or Ebay for a Cutlass cross member from 74 or earlier.

May 17th, 2007, 11:22 AM	#4 (permalink)
Oldsmaniac Registered User Join Date: Oct 2005 Location: NJ Posts: 702	I have some experience with this as I put a 455 in a 77 442 and installed dual exhaust. Im pretty sure the single hump cross member came about in 1975 when the only option was a catalytic converter and single exhaust. I used a cross member from an earlier car of which vintage or model I am not sure of but am pretty sure in was a Cutlass. The only problem was that the tranny mount was a single bolt mount and the older cross member was drilled for 2 bolt mount. I simply had to drill a new hole for the trans mount in the old cross member and possible some new holes on each end where the cross member bolts to the frame of the car....It was no big deal.