Hello I recently blew up the motor in my 1973 Pontiac Grand Prix so I am looking for a 400 v8 to replace the one I blew up. I could also use a 454 or a 455 but it must be a pontiac motor. Thank you email stevesmiechowski@yahoo.com or call/text 412 335 3821
“454” is a Chevy motor.
326, 350, 389, 400, 421, 428, & 455 Pontiac motors all share basic size/layout and will interchange in most chassis. The older motors ('68 & older) do not have both mounting pads for the motor mounts. '65 & later motors have the newer style heads/intakes that most aftermarket parts are built for.
What’s wrong with your motor?
These motors are fairly inexpensive to rebuild & parts are plentiful. If it is the original motor, you may be further ahead to rebuild it. Used engines are not always the best way to go, especially when those motors haven’t been made since 1979. The only “Pontiac” V8 made after 1979 was the 301. It was junk.
If not, I know plenty of people in the Pontiac parts business.
Thanks for the info. I am positive the motor is scrapped seeing as it crapped all of its oil and anti freeze on the highway. My only option is a replacement, if I do get a junkyard motor I will most likely rebuild or build it. I am really hoping to get a motor from 73 because of the stamps
I suggest joining: http://forums.performanceyears.com/forums/ and searching the classifieds.
There is some GP stuff over there. My screen name over there is 6 Grrrs.
if you get desperate i have a 400 chevy
Good website…also try www.classicalpontiac.com , it is another good Pontiac focused website.
I agree with SixSpeed…I would take a good look at the condition of your block before taking a chance on another used one…also remember that it’s fairly inexpensive (in Pontiac terms) to turn a 400 into a 455 these days.
Siamese bore is scary though. Thanks guys I’ll check those out
learn how to drive …and stop doing doghnuts in my work parking lot my boss grilled me for it…
Your just jealous that you don’t have the legal ability to do donuts
what did he grill u ? burger ? a steak or 2 ? 
whatever it was he probly ate the donuts and whatever was grilled