Thanks...I agree it might be the simplest path. Mine has been working fine since 1997. I will say the distributors I've been modifying sell for about $60, though and I think I paid about $15 for 2 of the clamps on Amazon, so that would add another $7~8. Just try not to hacksaw your thumb as I often do because it hurts and it could take longer to heal than you wish.
Here's one with a black distributor cap. And if you want a separate coil, you can do that and use the GM low rise distributor cap and the rotor that pairs with it. A 1978 230 engine will get those 2 parts for you. To each his/her own but I like the short path from the coil to the innards, so I just use the coil-in-cap type.
https://tinyurl.com/3pcfbv4xFor a bit of a heads-up, a friend mentioned he saw one of the distributors for the 216/235/261 and to his eye it looked like the bottom of the shaft had not been shortened. From the picture it looks like that to me, also. I agree this might be an easy mistake to make. Since the collar can be positioned anywhere, a person might misunderstand the importance of meshing the camshaft gear and the distributor gear and might think that step isn't necessary. Neither of us has bought one to check but
my suggestion would be to buy whatever you want and before you install it, compare it carefully with the stock distributor you have. If the HEI hasn't been shortened correctly the distributor gear could be running too high on the camshaft gear by as much as the thickness of 3 pennies and that could cause serious damage to both gears and a quick failure. It should look like what you see below and the tip end and the location of the gear should match with the OEM type. Good luck!
