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Been lurking for awhile and wanted to introduce myself proper. Trying to learn all I can on the Olds 403. Got one in my '79 Buick Estate Wagon that we pull an Airstream Argosy with and looking to up the performance a bit. Lots of knowledge folks here I see, thanks for letting me join in.
Lamar in Athens Georgia
Last edited by MrEarl; August 17th, 2019 at 04:33 PM.
Thanks guys. The wagon handles the tow well except for needing a bit more power. Sway bar added to the rear, heavier duty one to the front. New progressive coil springs and coil assist shocks on the rear and gas shocks on front. A set of LT load range 109 Uniroyal tires took the side to side squirrelly movement away and she hugs the road nicely in curves. Will be starting a thread soon to discuss some options on getting some more horsepower and torque
As for more power, there are two things to consider.
First is a lower rear gear, which will make it feel as the engine has more power. Most vehicles with factory tow options have lower rear gears to provide better pulling power. Do you know what gear ratio your wagon has?
The second thing is the low compression ratio on the 403 engines. I think they're actually around 8:1 or maybe a bit less. If you want more power from the engine, it likely would likely require an increase in compression and a suitable camshaft to compliment the compression increase.
I'd look into gearing first as that has always been the best performance increase in my experience.
The wagon came with full tow package so has the 3.23 limited slip rear differential. Had the TH350 rebuilt and a RV shift kit added. I’ll cover everything when I post the new thread in a day or so.
Very nice, I love it! Is that still a carburated car? If so maybe you would want to switch to a 455? Lots of torque there! Ill be looking for your new thread- sounds interesting.
look forward to hearing folks thoughts and opinions on the 403.
My opinion is it is a good engine. Even in stock form it's rated 320 ft-lbs torque and with its 8:1 compression ratio can run on low octane fuel. Lotsa cubic inches in a small block package. What's not to like about that?
My opinion is it is a good engine. Even in stock form it's rated 320 ft-lbs torque and with its 8:1 compression ratio can run on low octane fuel. Lotsa cubic inches in a small block package. What's not to like about that?
Oh, I definitely agree @Fun71 , what I probably should have said is look forward to hearing thoughts and opinions on making an already great engine even better. It has plenty of power for cruising around and actually tows the 4,500 lb Airstream OK except on some of the NE Georgia hills we've encountered. Re running on low octane, not sure about that, I've always used 93. Wouldn't mind plugging low octane into the formula I'll be working on for the upgraded engine build though.
August 17th, 2019, 04:24 PM
