Whats good or bad about them?
This is what is in my 68 442.

 

Nothing is bad about a 66 or 67 E Block 400..

 

Good: Forged crank, short stroke, proven performer, a far better choice than the G-block long-stroke 400 that was originally installed in a 68 442

Bad: Not the original motor, down at least 55 cu in from where you could be

 

I got a new HEI distributor and 8MM wires coming so I can adjust the timing better, valves are a rattling! Plus I have to install my Performer intake.

 

It's not the valves that are rattling. That's detonation.

 

I know that but more people understand "valves rattling" than detonation.
Back in the day when this all started the gas companies said it wasn't low octane gas causing problems it was the " valves making the noise" !

 

Been building these cars for four decades now, this is the first time I've heard the term "valves rattling" to mean detonation...

I'm also struggling with how changing to HEI allows you to adjust the timing better. Both the points and electronic distributors adjust exactly the same way - loosen the hold down bolt and rotate the distributor while looking at the timing light. Vac advance and mechanical advance adjustments are also the same in both.

Now, HEI is a GM term that refers to the coil-in-cap distributor. If you mean you are changing to an aftermarket electronic distributor with some sort of computerized advance curve that can be adjusted with a potentiometer, that's different, but it's also not "HEI".

 

I already have an HEI in it and its old. Im getting one with a better curve, adjustable pod, better coil and module.

 

The reason they said valves rattling to the best of my knowledge is becasue of the valves suppousdley banging on the valve seat due to no lead depostis to soften the blow of them closing but many have said that the have not heard this many have said yes. but detonation will sound sometimes like rocks in a coffee can .

 

Yea, my problem is detonation.
The curve came in around 2000rpms and rattled so I put in a heavy and light spring and it moved up exactly 500 RPMs. So with my new dist I can adjust the advance with a turn of a allen wrench and make it very easy.
I might have to drop my timing a little also and give and take until it stops.
The car is just a show car/ cruise in/ Parts getter, not a race car at all.

 

If anybody can hear that with the naked ear then they must be superman. More old wives tales. It's detonation, plain and simple.

 

No one said it wasn't detonation, but back in the day they called it "valve rattle" because it sounded like metal to metal knocking.
Anyway back to the original question of good and bad of a 67 400.
Since it has the .921 lifters do they still run the same cam as the smaller diameter lifter?

 

Agreed mark i was more or less just explaining how the " valves rattling" is one of those old wives tales and how it kind of came about.