Hi,
I am looking at a 68 firebird and the guy says that it is a 350-HO but I want to make sure. The vin # is 223678L105840, the numbers on the front of the engine are 00379831 ym and below that # are 25X108951 I don,t know the casting #yet. How can I tell if this engine came with the car and is it an HO.
Thanks for any info. Harold
YM is a HO block
Best way to check the car is correct to the vin is order a PHS report on the car. I did it on mine and was very happy I did. Gives you every option the car was built with.
http://www.phs-online.com/
I can confirm it. What is the head code? On center exhaust value.
VIN Data:
1968 Pontiac Firebird V8 Convertible
This car was the 5,840 made at the Van Nuys, California plant.
The car should be an automatic with #18 heads.
More info at PHS.
Year Engine HP Engine code Trans CR Cam Head Code BBL Carb No. Misc
1968 350 HO 320 HP WK M 10.5 067 18 1-4 7028269 Block Casting # 9790079
1968 350 HO 320 HP WR M 10.5 066 18 1-4 7028269 Block Casting # 9790079
1968 350 320 HP YM A 10.5 066 18 1-4 7028266 Block Casting # 9790079
1968 350 320 HP YP A 10.5 067 18 1-4 7028266 Block Casting # 9790079
320 HP
I have the WK
Don't steer the guy wrong. That YM is a 400 from a 1975 Bonneville. If it has its original heads they are 5C.
YM could be a 68 350.
Check the raised casting #'s on the center exhuast ports.
Cleaned up the garage some last night and found my 73 Pontiac parts catalog, so checked engine charts.
68 YM
FB and Tempest 350
Last two engine digits are 29.
066 cam
10.5 cr
4bl carb
distributor #1111282
320 hp
Did you find your 1975 parts book?
What you're saying would be right for a 1968 motor. But what you're telling the guy is something that ain't right about the motor that's in the car he's looking at. It's not the original motor. It's not a 350 HO. It's not even a 350. You won't need the PHS docs to confirm that.
Did you notice he posted the partial VIN number? It's from 1975, not 1968. The 1975 YM is a 400. Its NOT a 1968 YM 350 HO. The casting number will be 481988 (early), not 500557 (and not 9790079).
Saying it was a Bonneville motor was just a guess. As it turns out, it was a bad guess since it came from the old Kansas City plant ("X" in the VIN). 1975 production there was A body cars, so that makes it a LeMans or a Grand Prix engine - not a Bonneville engine (as I assumed originally).
Didnt check for other years, but just did. There is a ym in 75. 400 used in b-bodies.
Guess i should of been clear'r. Not say'n its a 68 350 HO.
The last 2 eng digits(29) vs (31) is the important note.
As well as # on r/r top of blk. 481988(up to 74-strong ones) vs 500557(75 and up-weak ones).
FWIW, the 6th digit of the vin is the yr that the car was built.