1985 Cutlass Supreme Brougham

HarleyJoe

n00b
Nov 14, 2022
1
1
I recently put together a 1985 Cutlass I have a 383 stroker with 425hp, 350 turbo transmission 2500 stall, and 4-11 gear. I have a Holley 600. I started out with a Street fire distributor with ignition box and coil. Had problems with it so went to a HEI distributor now having issues with the timing and looking to find what combinations others use
 

78Delta88

Master Mechanic
Supporting Member
May 23, 2022
406
43
SW Arizona
I recently put together a 1985 Cutlass I have a 383 stroker with 425hp, 350 turbo transmission 2500 stall, and 4-11 gear. I have a Holley 600. I started out with a Street fire distributor with ignition box and coil. Had problems with it so went to a HEI distributor now having issues with the timing and looking to find what combinations others use
On things like this, need a little more info such as symptoms, how is it acting on street when you drive it. Plus the carb sounds a bit small for your gears and stall. At 425hp I assume you wind it up more than 1800 on the highway.

Timing is a constant issue, several treads on this.

A few things to look at here:

1. Static Compression...
2. Dynamic Compression
3. Cam Grind
4. Cam LSA

Then the next is how do you want to drive it?

Basically if your at 9:1 or more you need to start about 6* BTDC. Especially if you are up around 175psi or more.

As the static compression goes up your base tune timing goes down, then you bring more timing in after the engine starts.

Then you look at timing curve and what works with what you have and how you drive it.

This also includes fuel; 86 octane or 93 or 104, etc...

Too little timing and you have a slug.

Too much timing and engine damage and you still have a slug.

Figuring you have flat tops and good heads... Headers and cat backs....

Try 6* at BTDC, Ported Vacuum, HEI Medium Springs with Medium Weights. 50cc on the the Holley pumper(s), all in timing at 32* at 2500 - 3000 rpm.

If your Holley is out of the box, go up two steps on the primary jets. Make sure floats are set right and you have good solid fuel pump pressure.

On the TH350 get the Red/Black stripe modulator and turn it in about 4 turns. Make sure kick down is correctly installed.

Then go drive it.
 

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