This is a new thing for me. Forums and restoring a 48 Pontiac Silver Streak. So bare with me, I'm old and a slow learner sometimes. I just got the car and would like to start with all fresh fluids. It is a restoration started by a gentleman who sadly passed away before he could complete the car so there are questions I can't get answers for. I don't know for sure what was done in regards to the engine oil and tranny fluid. I realize there is not a typical oil filter on this car ( straight 8) so I want to drop the pan and clean it out etc. Can this be done without removing the motor? Also are there things I need to know when I get to changing the tranny fluid as well? Thank you for your help.
I'm sure those who know the vehicle will offer some solid advice, but this site really is not a "restores site". Best of luck in the build.
I would pull the dipstick, and look a the oil....is it clean? is it full? If so, I'd leave it be. Then I'd get the car up in the air and supported solidly on stands, and remove the fill plug on the side of the transmission, and poke a bent piece of wire into the hole. How full is it? And do the same to the rear end. If they're within a half inch of the bottom of the fill hole, I'd leave them be. The fluids I'd worry most about would be the brake fluid, gasoline, and the coolant. Oil lasts a long long time, and doesn't go bad. But coolant usually has rust inhibitors in it that go bad over time. And brake fluid on old cars with vented master cylinder caps absorbs moisture. Gasoline also absorbs moisture, since most of it today has alcohol in it. If you don't know when all these fluids were last changed, you probably ought to start with them. Might want to consider inspecting and possibly replacing the rubber parts in these systems as well, as they tend to go bad. Welcome to old cars, have fun!
I differ with Jim in a few areas, if the car has been sitting for 20+ years, the clean oil you see, might be because all the crap is now at the bottom of the pan. When you fire it up, it'll then recirc through the engine. I'd drain, then flush the engine. Tranny probably good without the effort if it has oil in it, assuming manual.
I don't know, but find a Pontiac type restores forum, I'm not saying you should leave or anything, but info you seek may take a bit of time to get an answer here. Now, if you asked how much to chop or section it, you'd have two pages of replies in a day
The first thing I'd do is get a factory shop manual for that car. You can find them at swap meets (although that's probably not a good choice this year) or on eBay. Besides originals, you can usually find reprints - either as hard copies or electronic on a CD-ROM. If all else fails, an old Motors manual is useful. They cover a number of years in each edition so you just need to find one that's close to 1948. They're pretty common and usually pretty inexpensive. Besides here, the most active Pontiac website is https://forums.maxperformanceinc.com/forums There's a tech section there for 1960 and earlier cars, although unfortunately there aren't many people with Pontiacs that old. Think about joining the Pontiac-Oakland Club International (POCI.) Their website doesn't see much action but the monthly magazine is good, and there are tech advisors who can help with questions. There are also local chapters of the club in most areas, where you can meet up in person with other Pontiac owners. https://www.poci.org
Check out PhilA's " mild custom '51 Pontiac Chieftan" thread. Sent from my SM-T350 using The H.A.M.B. mobile app
This is helpful information...which you probably should have included in your first post Again, I'd be looking at things and assessing condition, before just automatically assuming you need to do stuff. If you can post pictures of the engine, and the underneath of the car, and tell us a bit more about the condition, we could probably offer more helpful advice. Visiting other forums might help get a few different perspectives, but they don't seem to have the breadth of knowledge you'll find here.