How to drive after rebuild?
 

Car is back from the shop with a freshly rebuilt 3.2.
I am planning on taking it easy for the first 1000mi,
that is, avoid reving over 4K. Two oil changes. One at
500mi the other at 1000mi. Am I being overly
conservative?

Better do a search on this. It was debated a while ago and the general consensus was to NOT take it easy for the first 20 minutes, and if the cam has been reground it needs to be kept at varing revs over 3,000.

Nice fresh engine! That will good :)

Hey I just rebuilt my own 3.2 and just got it back on the road! According to Wayne's book avoid revs past 5k rpm, but be agressive and not afraid to run it up through the gears to that 5k rpm limit. Try to avoid long periods of running at just one rpm on the highway. In his book he recommends running the engine at 2000 rpm for 20 minutes the first time you start the engine, then change the oil and filter. Go for a couple of drives. After 30-50 miles change oil and filter again. At 500 miles change oil and filter. Check torque on head studs and adjust valves. Then you are good to go with no limitations.

So I am not conservative enough...

Drove mine 120 mile to a historic race meeting. Varied the revs and went up a down a few hills. And then thrashed the crap out of it for 2 days.

That was 2 years ago and it is still going well. It has a bit more power now that it is not so tight.

I would recommend you drive it the first 1000 miles the same way you intend to drive it from then on.

2 questions:
If not varying the RPM is a bad thing, then why run it for 20 minutes at one rpm?

Why is it bad to run it beyond 5k? I've heard 6k, 4k, whatever, but don't you want the engine broken in at rpm beyond 5k? Like with an early S engine, there are 2200 rpm MORE where you've never run it?

General consensus on this board is to break the engine in using dinosaur oil, keeping revs above 2500 - 3000rpm for the cam lobes to harden for 20 minutes, then drive it hard, but not too hard, making sure you use enough gas pedal to ensure the rings seat properly. Also decelerate from medium-high revs on the overrun to get excess oil off the cylinder walls.