1972 grand prix idle speed?

Question

Greetings, I have a 1972 Grand Prix with either the 400 or the 455 engine in it (just got it and not quite sure). Does anyone know what the idle speed would be for either engine? It has a holley 4 barrel double pumper carb in it as well.

Thanks!

Answer 1

somewhere between---900.....1100..good lucK

Answer 2

whatever makes the car run smooth, and does not hesitate when you step on the gas or stall when you let go of the gas.  Engines vary in their health.

Answer 3

The Dodge Man has the right answer. Usually the 1972 Pontiac Grand Prix Model J has a 455 cid as standard engine, the 1972 Model SJ has the 400 cid engine as standard engine. (In 1970 the Pontiac Grand Prix Model SJ came with 455 cid engine as standard engine, and the 1970 Model J came with 400 cid engine). How do I know, I still have a 1970 Pontiac Grand Prix Model J 400, TH-40 tranny, and I had a Starlight Black 1970 Pontiac Grand Prix SJ 455/370HP with TH-40 tranny, my very best friend has a 1972 Pontiac Grand Prix Model J with 455, TH-40 tranny. By the way you will need to find engine letter codes to see if the original engine is in your 1972 Pontiac Grand Prix, for example my 1970 Pontiac Grand Prix had the 1970 Pontiac GTO base engine 400 cid/ 350 HP (YS) engine in it when I bought it!

Answer 4

you need to get that one idling at about 650 -700 in drive,if you can get a good steady 650 from it that will be good,no more than 750 or 800 in neutral,it shouldnt die down much when you drop it in gear,if you can get aroind 650-675 in drive that will be real good on it,but the mixture screws are going to have to be right to achieve that rpm from it,good luck,