I haven't driven it since changing the timing curve. Now I'm getting 10-12* from the vac advance and 30 from the distributor once it's all in. I thought about running a clutch fan but I don't think I have room. Right now I have a pretty thin electric fan and it's only about 1" from the snout of the water pump.
Why not? Did you move the engine forward? Is this not a stock application? The factory fit a mechanical fan. What did you do to change that?
The fans when off could be limiting air flow through the core. A lot depends on exactly which fans and the shrouding you are using. That's why I don't like them. Having said that, I am sure some guys are using them with great success. If I had any problems at all with cooling, I might consider going electric, but I don't, with a completely stock clutch fan set up.
I'm running a 455 in a 67 Skylark using TA frame pads and engine mounts. Everything is as far back as I can go without running into the tunnel. The front of the water pump is probably about 2-3 inches from the radiator. I'll post a picture when I get home.
The problem may be that you are using the long water pump. Some 455's did use the long pump, but if you are putting that 455 into a 67, you need to use the short pump. That would mean matching pulleys as well.
