Moroso 72300 Advance Curve Kit, Fits GM HEI Distributors

Removed the old springs and weights and installed this set. Installation is as super easy. I ended up needing the black springs as the 454 kept knocking with medium springs. Perfect replacement for the old.

I had installed an aftermarket HEI which had a horrible timing curve. Using this recurve setup i was able to use one light and one medium spring to bring in all my timing by around 3200rpm. The timing advance starts around 1100rpm and comes up perfectly smoothly through the RPM range. This fixed a part throttle bog I had when towing heavy trailers with my truck and generally increased my towing experience. No directions are included, but if you google Moroso 72300 you'll find the instructions which show the different spring characteristics. I would 100% recommend installing these.

I was having a hard time nailing down my initial timing because it was jumping all over the place. This kit fixed that. However, I’m only getting 16 degrees of mechanical advance with this kit in my HEI. I have a big cam so my initial is at 16 as well giving me 32. Runs hard but I’m also safe from detonation. I’ll need to carefully shave the weights or center plate to get more. I’m satisfied for now.

Ebay HEI on 383 with Howards Roller Rattler cam and Flotek heads. The stock advance on the HEI was allowing for too much advance at total RPM. Installed this and the timing curve is perfect and total timing spot on. If you have an Ebay HEI and an aggressive small block this is a must.

Purchased to upgrade a GM hei distributor. Three different sets of bushings are included, the only one even close to fitting were the black ones. They are incredibly tight going into the included weights. Next time I will use the original weights and drill them out so the bushings will fit them. I feel the original weights are a much better setup. I used the medium springs ,its working fairly well. I will experiment with the other springs in the near future. Be sure to take a few pics of the original setup so you can install the new stuff correctly.

Ok

good quality working good perfect fit

Fixed my erratic base timing issue. I did have to use a combination of the light and medium spring to get my total timing to come in where I wanted it.

Only used the middle strength springs (silver) on SBC pro billet with stock weights. Timing all in by 2800 rpm.

Wanted to ad some timing on my monte carlo and this worked as expected

Comes with all the parts to give your HEI distributor a performance ignition curve and pick up a noticeable power improvement.

Installed new weights with medium springs. Found it did not provide enough advance at rpm, it was very retarded. Ended up using stock weights with medium springs and it really helped wake the truck up. If nothing else, its worth it for the springs to play with the advance. Make sure your timing light is up to checking total timing before installing.

Did not go to high enough RPM at full advance used old and new parts to move curve higher.