1979 Trans Am Olds 403 Camshaft?
- Thread starter baumb24
- Start date
Has anyone ever put this cam in an Olds 403 79 Trans Am?
Bone stock 55k miles, all original.
Is it worth the upgrade?
Bone stock 55k miles, all original.
Is it worth the upgrade?
Hi there & welcome to the forum!
The one significant factor in holding back an Olds 403 in a ‘bird is compression, namely the lack of it.
Just under 8:1 CR is too low to take full advantage of any gains from a cam & or intake upgrade.
This doesn’t necessarily mean ripping the block apart & fitting flat top pistons, although that would be the ideal solution.
Achieving 1 & a half-point increase in compression is quickly done by installing 350 small chamber heads early or, even better, a pair of aftermarket aluminum heads, Edelbrock, etc.
The main factors are, of course, how much investment is compared to achieve the best results & that’s all dependant on what you are hoping for.
Better quarter times?
The one significant factor in holding back an Olds 403 in a ‘bird is compression, namely the lack of it.
Just under 8:1 CR is too low to take full advantage of any gains from a cam & or intake upgrade.
This doesn’t necessarily mean ripping the block apart & fitting flat top pistons, although that would be the ideal solution.
Achieving 1 & a half-point increase in compression is quickly done by installing 350 small chamber heads early or, even better, a pair of aftermarket aluminum heads, Edelbrock, etc.
The main factors are, of course, how much investment is compared to achieve the best results & that’s all dependant on what you are hoping for.
Better quarter times?
Sorry, I forgot to add this, but it’s relevant. Have you considered changing the rear gears?
My ‘79 T/A has it’s original 403 with bone stock internals, so I understand how the car’s acceleration could underwhelm you.
The cheapest & easiest way to knock a clear second or maybe more is to install some steeper gears; the original was prob 2.41:1 on a stock 403 or 2.73:1 on a WS6 optioned car (like mine).
There’s no point in leaving these gear ratios installed if you want stronger acceleration, especially if you still plan some engine mods.
I advise spending a couple hundred on a set of gears & enjoying the gains while you plan the rest of the modifications.
If you haven’t already done so, check out the Mondello Perf website.
https://mondelloperformance.com/
My ‘79 T/A has it’s original 403 with bone stock internals, so I understand how the car’s acceleration could underwhelm you.
The cheapest & easiest way to knock a clear second or maybe more is to install some steeper gears; the original was prob 2.41:1 on a stock 403 or 2.73:1 on a WS6 optioned car (like mine).
There’s no point in leaving these gear ratios installed if you want stronger acceleration, especially if you still plan some engine mods.
I advise spending a couple hundred on a set of gears & enjoying the gains while you plan the rest of the modifications.
If you haven’t already done so, check out the Mondello Perf website.
https://mondelloperformance.com/
I'm aware of compression issues and weak bottom end.
I'm looking for a little low-end torque, and lopey idle for this season.
Next winter, I'll build up the 403 or put a Pontiac 400 or 455.
I'm looking for a little low-end torque, and lopey idle for this season.
Next winter, I'll build up the 403 or put a Pontiac 400 or 455.
Okay, I'm sold on the rear-end gears.
I plan on going to a bunch of shows with highway driving.
I'm thinking 308.
I plan on going to a bunch of shows with highway driving.
I'm thinking 308.
Yeah 3.08 or 3.23’s would both work fine for highway (70 ish) cruising while still giving a noticeable improvement in acceleration, especially from a standing start.
Are you still using the factory TH350?
The 79’s with Pontiac 400’s & 4 speeds came equipped with 3.23s from the factory.
I was hoping you wouldn’t believe all the negative talk surrounding the 403’s open window bottom end; I’ve never seen one fail from anything other than poor maintenance & assembly.
Are you still using the factory TH350?
The 79’s with Pontiac 400’s & 4 speeds came equipped with 3.23s from the factory.
I was hoping you wouldn’t believe all the negative talk surrounding the 403’s open window bottom end; I’ve never seen one fail from anything other than poor maintenance & assembly.
Yep, stock tranny.
I'm having it serviced and a shift kit installed.
I'm having it serviced and a shift kit installed.
Can I have the ring and pinion replaced?
Or should I replace all the bearings as well?
Or should I replace all the bearings as well?
Yeah, of course, assuming the bearing components didn’t look worn or get damaged on removal & they weren’t noisy to start with.
You’ll still have to set up the lash, tho, as every casting is different.
You’ll still have to set up the lash, tho, as every casting is different.
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