downpipe compatability with L48 stock exhaust manifold

[ace]

x33RS

Definitely will heed your advice about using  a mandrel bent downpipe.  If I stay with a 2.25 inch stock transverse system I will have the performance shop replace any crushed type downpipe that comes with a purchased system with a mandrel downpipe.   I do know that the Pypes transverse system comes with 2.5 inch pipes and transverse performance muffler.  Since the system is header back I have the option of purchasing a 2.5 inch downpipe from Pypes.     

Local performance exhaust shop said the shop usually includes in their assembly of a purchased system a crosspipe (akin to an H pipe) for balance. 

Overall goal is to increase performance over stock 2 inch system and maintain the stock appearance. 

Ace

[ace]

Crossboss:

I am happy to own a car that is "smog exempt", but I have to tell you that it isn't always easy buying parts for the car.

I had a phone discussion with Summit a year ago when I tried to purchase a pair of their Dart iron eagle heads and the Summit version of the Dart iron eagle.  Since neither of these pair of heads had a C.A.R.B number, Summit said was it  illegal for them to sell the heads for a daily driver vehicle.   The only pair of iron heads that can be sold "legally" in California by Summit  and other vendors (like Jegs, Competition Product etc.) are World Product Heads (which sells a version of the Dart II heads).  What was interesting is that the World Product heads have nearly identical specs as the Dart iron eagle ss heads.  Essentially these heads are stock replacement heads for the old Camel humps. I discussed with the  Summit rep. that the Air Resources Board allows the use of heads that are stock replacement and does not require a C.A.R.B code.  Summit said they have too big a footprint in the aftermarket industry to take chances selling items that do not carry a C.A.R.B. code.   

       According to  C.A.R.B. '67 and prior California cars are automatically C.A.R.B. exempt.  Years '68- '76 are smog exempt (exempt from inspection), but are not C.A.R.B exempt.   Perhaps someday policy will catch up with practice.  Most enthusiasts are not worried about violating a code that will never be enforced, but vendors sure seem to worry about violating the code.

       In any case, Summit suggested I look into purchasing Edelbrock Performers or AFR 180 aluminum heads that carry a C.A.R.B number.  Given that I already had decent stock heads, I decided to have the originals pocket ported and the engine seems to run fairly strong -even on 91 octane.

Ace

[crossboss]

Crossboss:

I am happy to own a car that is "smog exempt", but I have to tell you that it isn't always easy buying parts for the car.

I had a phone discussion with Summit a year ago when I tried to purchase a pair of their Dart iron eagle heads and the Summit version of the Dart iron eagle.  Since neither of these pair of heads had a C.A.R.B number, Summit said was it  illegal for them to sell the heads for a daily driver vehicle.   The only pair of iron heads that can be sold "legally" in California by Summit  and other vendors (like Jegs, Competition Product etc.) are World Product Heads (which sells a version of the Dart II heads).  What was interesting is that the World Product heads have nearly identical specs as the Dart iron eagle ss heads.  Essentially these heads are stock replacement heads for the old Camel humps. I discussed with the  Summit rep. that the Air Resources Board allows the use of heads that are stock replacement and does not require a C.A.R.B code.  Summit said they have too big a footprint in the aftermarket industry to take chances selling items that do not carry a C.A.R.B. code.   

       According to  C.A.R.B. '67 and prior California cars are automatically C.A.R.B. exempt.  Years '68- '76 are smog exempt (exempt from inspection), but are not C.A.R.B exempt.   Perhaps someday policy will catch up with practice.  Most enthusiasts are not worried about violating a code that will never be enforced, but vendors sure seem to worry about violating the code.

       In any case, Summit suggested I look into purchasing Edelbrock Performers or AFR 180 aluminum heads that carry a C.A.R.B number.  Given that I already had decent stock heads, I decided to have the originals pocket ported and the engine seems to run fairly strong -even on 91 octane.

Ace

Ace,
Thats amazing, I never encountered that with Summit. Maybe it was just that sales man? As I suggested, try the line 'for off road use only' or this might be a bit of a hassle, have the parts shipped to a buddy out of state, then he can ship them to you. OR as you mentioned buy the CARB compliant stuff. Anyways, it seems you are quite happy what you have now, so that just might suffice for now.