Hello guys,

I have a 502 465HP Carb 1992 flat tappet with 170h. Thunderbolt IV.

I want to ensure a solid spark. After reading all old treads I found NOT good idea to try any aftermarket coil like MSD.

Soo my plan it to go OEM parts:

- distributor cap: 805759T1
- distributor rotor Assy: 805760
- Ignition coil: 300-8M0079202

Also I want to upgrade the wires from 6mm to 8
mm. Do you have any recommendation about wires?

About the coil. Do you have any opinion about the Hardin Marine?

https://www.cpperformance.com/p-16686-hardin-marine-high-vibration-ignition-coil.aspx?srsltid=AfmBOoqJ0oCAW3VoioFqCQ_tQESNseX-0dCZPEB1Wm8n-hmZ-WezxCaP

thank you,
Doc.

The stock ignition (TBIV) is pretty reliable. I would suggest just to run stock ignition and make sure you are getting the full advance around 34 to 36 degrees. You may have to change the ignition module to do that as long as you have good fuel available.

I wouldn't discount not replacing the ignition sensor (pick up) in the distributor. The old ones are exposed and go bad. New ones are sealed. I’ve done a lot last few yrs on 20-25yr old boats.

Just a mild suggestion.

Thank you for the tips. New sensor and 34-36 advance 👍

No reason to replace the coil. The stock merc plug wires work fine and I would use OEM merc ones

Wuick search on oe wires shows $118 most places, then a few around $101-$102. Like here:
https://partsvu.com/products/mercury...AzTVgbMDNMBonc

The red ones (above are blue) are cheaper at $88

https://partsvu.com/products/mercury...zvDPg4f15zEub7

Thank you!!

Cheapest OEM sensor i found quick search is amazon: $91.03

Then same place as thecwires

https://partsvu.com/products/mercury...2#product-info

Again, i did just quick search. The ones i bought to replace those failing (and failed) sensors where from that same amazon link. They are real quicksilver (oem) parts.