When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
What is the best way to find the options my 81 was equipped with ? I am trying to determine if it had the YF5 option for California emissions as there are 2 part numbers listed for the carb for an automatic. I would love to know the difference between the 2 carbs and which one is the correct carb for mine. is there any gm manual that is the go to for parts or identifying the correct options that would speed up the process of restoring the oe ? I know from the vin it was manufactured out of st louis but as for what state it was shipped to or sold from I have no idea.
I have a Ca one as I said.
the 3rd number you found is new to me.
only thing I did read is "some" have an ISC.
I have never seen or heard of one actually used.
I suspect cpu/ecm would be different as would wiring.
or it is a service replacement?
hhm they have a california emissions option .. So there must be some differences .. I still need to determine how mine was equipped ..and what the differences were. ... I think it has to do with the mixture control solenoid on the carb but not sure and i assume maybe the ecm .. Wiring like u said ... Ill do some digging ....
hhm they have a california emissions option .. So there must be some differences .. I still need to determine how mine was equipped ..and what the differences were. ... I think it has to do with the mixture control solenoid on the carb but not sure and i assume maybe the ecm .. Wiring like u said ... Ill do some digging ....
my build sheet was under driverside rear cargo area carpet.
service manual only lists 17/18
Well i decided to look at the engine serial .. And things took a strange turn ... Its coming back as a 76 c10 or 79 c30 if im reading correctly .. Id really like to meet the genius that put that one in if thats the case considering they went back with the original parts . im leaning crate engine or unload it .. Unless it wakes up with a hei distributor .. And says ive had some work done...
You can purchase a copy of the dealer invoice from the GM Heritage Center for $50-. It doesn't work for most C3s, but it should work for ~78 and later.
You can order a copy of your invoice through the Vehicle Invoice Collection (via email or phone).
that would be the 76 engine. 77 or 78-up had a smaller, squarer stamp pad. 81 are not big collector items. originality is a non-issue. the car's condition is it's value. that 76 pick up engine is just fine, unless it is not. if it doesn't smoke or knock or blow steam, get a decent distributor on it and get it timed up to 36-38 at full advance. and you will be surprised cuz it is now a 290 ho engine. the 165 hp numbers are a result of overly conservative timing for emissions and creative accounting for NTSB. and the truck version may well have flat pistons, not dished. don't dump the car for a wrong number stamped on the block.
this is a 78 and newer pad.
Last edited by derekderek; Nov 24, 2022 at 07:48 AM.
Thanks .. It was a fresh rebuild from what i was told when i bought it .. I guess on a positive note i wont feel bad for cleaning up the engine bay .. I did email lar for his timing information .. Still waiting on response .. But this helps
Got the carb back on after rebuild .. Rotated engine .. Got to pick up a few things this am ..replace thermostat and add antifreeze .. Fire extinguisher ... See if it will crank ... What type of oil is recommended .. I usually run valvoline full synthetic .. So was thinking 10w 30 with some lucas zinc additive
make sure you have power to that electric choke. otherwise you will have to loosen the round black cover and turn it to open the choke as it warms up. we all hate rubber fuel lines and clear plastic filters. but as long as fire extinguisher is right there... as far as options, 81 didn't have many. they had 1 engine. 4 speeds were rare. power windows and seats may be about all that was optional in the interior. i am sure all were AC, PS and PB. it was less a sports car and more a 2 seat luxury cruiser by 81.
c3 options identification
