Well, my problem all started when I bought my car, a 1992 RS. The seller told me that it had a 350 engine in it, and since he is a friend of my dad and I was a newb, I trusted him. So I bought the car and learned later that night that the only RS cars that came with 350s were the B4C versions, and since mine is a heritage edition, I was pretty sure that I was stuck with a 305, which was no big deal.

It was no big deal until my dad started talking with the guy who sold me the car again, and the he was dead sure that there was a 350 in there. So with this new info, I went out to find what engine I had by finding the block casting number. I looked and looked all over behind the driver side cylinder head and found nothing (probably due to all those damn wires), so I tried a different route.

I was reading here and the #6 on the picture caught my attention, so I thought I'd look for that number. I crawled under my car and looked around and on the front of the block on the drivers side were the three numbers: "638." I assumed that these were the last 3 parts of the casting number, so I went and checked the numbers and came out with 2 different engines: a 327 from a 68 truck or a 350 from the years of 87-95.

Now, the real problem I have here is: Is the number I found on the front of the block really what I think it is, and if it isn't, what is it?

Sorry about the long post, but I am really confused here and need help.

 

I have seen the last 3 digits from the block number right where you found it, I doubt it's a 327 only because they are harder to find. it probably is a 350 only because it makes more sense. did your dads friend buy the car new or used? if he got it used it could have had the motor changed or even ordered with a 350. check the vin number and see what it says for an engine size. also look for the RPO numbers, they would tell also.

 

The VIN number and the RPO codes both say that the car orignally came with a 305, and yes, the person that I bought it from did buy it used, so there is a very good chance that someone had swapped the motor out before he owned the car. Thanks for the help, I was really confused about all this. If you look at the engine bay everything looks like it came from the factory that way, or maybe I just haven't seen enough bone stock bays to tell exactly.

 

638 is definitely a 350 block. Somebody probably swapped it in there. I doubt it could be ordered that way. I know of no mechanism (RPO code) for ordering one in one of those cars, other than as a B4C, which would be a TPI 350.

It's really rare to get one of these cars, and have the seller swear it's a 350, and for it to actually be a 350. Seems like around selling time, 305s have a way of magically turning into 350s for the purpose of the sale. In fact you might be the first person I have ever seen that got one with that tale, where it turned out to really be a 350.

Congrats!!!

Of course, there's an awful lot of varieties of 350s, some of which are a whole lot better than others. Check the head casting numbers next. That will tell you if you have TPI heads, 70s smoggers, double-humps, truck TBI swirlies, etc. Heads are the key to how well a motor runs, so that will be the next step you'll need to know.