WTB - 2.5" Exhaust manifolds
11-05-2015, 06:18 PM
#1
Racer
Thread Starter
WTB - 2.5" Exhaust manifolds
Looking for a pair of 2.5" exhaust manifolds for my '63. Going to build a 340 HP motor for my winter project. 
Does anybody know the casting numbers I should be looking for?
Does anybody know the casting numbers I should be looking for?
11-05-2015, 06:42 PM
#2
Race Director
'63 340 HP is:
RH - #3797902(1)
LH - #3797901
RH - #3797902(1)
LH - #3797901
11-05-2015, 07:37 PM
#3
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2023 C1 of the Year Finalist - Modified
2015 C1 of the Year Finalist
Yep, 
11-05-2015, 07:56 PM
#6
Racer
Thread Starter
11-05-2015, 07:59 PM
#7
Racer
Thread Starter
Thanks for the info.
11-05-2015, 08:14 PM
#8
Le Mans Master
Surprisingly, the offshore rams horn exhaust manifolds are pretty decent. You can find them sold by just about everyone including Summit, NAPA and Rock Auto. You'll find them offered by Dorman Products.
Mike T - Prescott AZ
Mike T - Prescott AZ
11-05-2015, 08:56 PM
#9
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St. Jude Donor '07
Rock Auto
DORMAN 674504 {#3797901} C.A.R.B. Approved; Hardware: 3 Studs, 3 Nuts, 3 Washers, 3 Lock Washers; Gaskets: 1 Flange
Left; FI; Legal For Use In California and New York
$43.89
DORMAN 674503 {#3814970} C.A.R.B. Approved; Hardware: 3 Studs, 3 Nuts, 3 Washers, 3 Lock Washers; Gaskets: 1 Flange
Right; FI; Legal For Use In California and New York
$46.79
Bill
DORMAN 674504 {#3797901} C.A.R.B. Approved; Hardware: 3 Studs, 3 Nuts, 3 Washers, 3 Lock Washers; Gaskets: 1 Flange
Left; FI; Legal For Use In California and New York
$43.89
DORMAN 674503 {#3814970} C.A.R.B. Approved; Hardware: 3 Studs, 3 Nuts, 3 Washers, 3 Lock Washers; Gaskets: 1 Flange
Right; FI; Legal For Use In California and New York
$46.79
Bill
Last edited by wmf62; 11-05-2015 at 08:57 PM.
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Shift_Happens (11-05-2015)
11-05-2015, 09:39 PM
#10
Advanced
Those are really good prices. Many years ago I bought some 901 & 902 manifolds at Bloomington Gold swap meet for $100.00 ea. I have them on my 66 w 2.5 inch sidepipes. Really sound great, but gotta keep the windows up on a long cruise. I have a factory A/C coupe so that helps.
11-05-2015, 10:22 PM
#11
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2023 C1 of the Year Finalist - Modified
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Billl,
The Chinese 2 1/2in versions are sold in the USA by Dorman through various sources. As already mentioned, Rock Auto has the best prices on them.
I think I have bought 3 pair in recent years and they seem to be VERY GOOD quality. The Chinese versions DO NOT have the casting numbers which are on genuine GM manifolds, but if you are happy without having casting numbers, then they would ba an excellent manifold to use.
Below are comparisons between the Chinese version and original GM 901 and 902 versions (Chinese on top).
11-06-2015, 01:04 PM
#12
Racer
Thread Starter
Billl,
The Chinese 2 1/2in versions are sold in the USA by Dorman through various sources. As already mentioned, Rock Auto has the best prices on them.
I think I have bought 3 pair in recent years and they seem to be VERY GOOD quality. The Chinese versions DO NOT have the casting numbers which are on genuine GM manifolds, but if you are happy without having casting numbers, then they would ba an excellent manifold to use.
Below are comparisons between the Chinese version and original GM 901 and 902 versions (Chinese on top).
The Chinese 2 1/2in versions are sold in the USA by Dorman through various sources. As already mentioned, Rock Auto has the best prices on them.
I think I have bought 3 pair in recent years and they seem to be VERY GOOD quality. The Chinese versions DO NOT have the casting numbers which are on genuine GM manifolds, but if you are happy without having casting numbers, then they would ba an excellent manifold to use.
Below are comparisons between the Chinese version and original GM 901 and 902 versions (Chinese on top).
11-06-2015, 01:27 PM
#13
Instructor
11-07-2015, 10:04 AM
#14
Instructor
11-07-2015, 11:19 AM
#15
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St. Jude Donor '10
It's left side but with a casting number of 3846563. It has front accessory holes so it may be for a different year. 135. shipped
Last edited by LSUvetteguy; 11-07-2015 at 11:20 AM.
11-07-2015, 11:55 AM
#16
I've got a couple sets of NOS '901s AND '902s. They've never been mounted and include the original boxes. They have the tube, so are not accurate for the fuelie motor. $250 each.