Hi,

My son is the proud owner of an 89 Pontiac Safari wagon with a 307 Olds V8. We live in California. I think his motor gave up the ghost last night. Given California's smog emission and testing requirements, we have to live with a smog pump. Rebuilding his original motor isn't out of the question, but what other options does he have? Would any other Olds motors swap without major changes? We're not looking for a street terror, but being able to go up a hill in the left lane would be a welcome change!

Thanks for your time.

Don
birdnherd64

 

403

 

Welcome. To quote Clint Eastwood, do you feel lucky?

All 1964-1990 Oldsmobile motors look externally identical to the untrained eye. All small block Olds motors (260, 307, 330, 350 403) ARE externally identical. The big block Olds motors (400, 425, 455) look the same but have a taller deck height and thus a wider intake manifold. If you were to use a 350 or 403 Olds motor, it bolts in and can be dressed to look exactly like the 307.

The biggest problem you will have is the ports in the heads that the A.I.R. pipes attach to. No 403s were made with A.I.R.. The heads have the bosses for the tubes, but the holes are not machined.



Ironically, Olds motors sold in CA in 1966 and 1967 DID use A.I.R. If you could possibly find a set of heads from a 330 motor from that period, they would bolt to a 350 or 403 and allow you to connect the A.I.R. system. There might have been some 350s built with A.I.R. in the 1979/1980 model years, but I don't know for sure. You might even get away with running the 5A heads from a 1980-84 307 on a 350 if you installed larger valves. Everything else from the 307 bolts to any Olds 350 or 403, so it won't be hard to make one of these look like the old 307. Of course, this only works so long as no one checks casting numbers...

(No, I do not expect a smog test technician to know or check for the correct casting numbers, but a referee station would)

 

Thanks Joe, that is great information! I'll put my son to work looking for a rebuildable 350 or 403. He has a friend that owns a machine shop that he can discuss the necessary machine work. He just passed smog last month, and wth your information I hope we can keep his car running and avoid the referee in the future.

I appreciate your time.

Don

 

We may have finally found a rebuildable 350. It has a block casting 395558, and is (from what I understand) a 1972-1975 model. Will I be able to install the Heads, Intake, mounts, water pump, and externals from my son's 1989 CA emission controlled 307 to this 350?

 

You could but those are swirl port castings have very small ports. You could get them ported and put 350 valves in them. I am pretty sure you can only enlarge their tiny ports so much though. Either way keep the compression at less than 9 to 1. I have found mid 70's Olds 350's in great shape. With that stock short block, you 307 heads intake with some work and a early Vin 9 or smog 455 replacement cam, you will gain power. You should be around 8.5 to 1 compression which is what you want with 60 degrees part throttle timing. Also use the cast iron exhaust manifolds off the 350.

 

395558 block casting was used from 1968-1976. Check the VIN derivative stamp, which will tell you the exact model year of the block. The second character of the VIN derivative is the model year.



As noted, the 7A heads on the 89 motor have tiny ports. The intake and exhaust manifolds match those ports. Consider getting a set of 1980-84 5A heads, which have the larger ports and provision for the A.I.R. system. Then use the matching A4 intake from and cast iron exhaust manifolds the 1980-84 307. The 350 will thank you. Note that the 350 block uses 7/16" head bolts whereas the 307 used 1/2" head bolts. The larger head bolts were intended to make up for the flexibility of the thin-wall, open main web 307 block.

The CCC system will run the 350. You may want to change the secondary metering rods in the Qjet to ones from a 350. The secondary side of the carb is not computer controlled, so this is no problem. The other thing is that the 307 carb has a stop on the secondary air valves that restricts opening to 70 degrees. File this stop to get a full 90 degree opening as was the case for "real" Qjet carbs.