Ok, now that it's done, I'm going to drive it to the shop to get the exhaust done. That's about 20 miles.

I'll change the oil after that.

Then I'll do another few miles, 200 maybe, change the oil again.

What should I be looking for during breakin? There are no leaks. I am keeping my eye on the oil to ensure there's no antifreeze in there, and vice versa.

What else should I be doing, and for how long? What should I be keeping an eye on?

Thanks.

Drive it like you stole it!!
Just kidding - actually I'm interested in the responses too!

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Yeah, it would be nice to know what to look for during the first few hundred miles in case something is going to blow.

My primary concern is the head gaskets. If they last 500 miles, they should last forever, I hope.

Every time I fire it up, I get under the car. No leaks, nothing. Oil looks spotless on the stick, as it should.

I'm nervous about head gaskets too. It just doesn't seem like 60-75 ft.lbs is a lot of clamping force, but I guess multiplied 17 times across the head it is pretty tight. I used an .026 gasket and there is little or nothing to squeeze.!!! I also used the ARP thread sealant which has me worried too.

Watch out for Wascal Wabbits!

Retorque the heads when you get home.

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Did you install your heads yet?

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Got all three goin' for ya tonight!!!! Lots of poppin back and forth while sitting in front of the TV!!

Good Luck! I hope you make it with open headers. Not only Cops but that can throw off the O2 sensor/sensors.

I thought the new consensus is to not retorque head bolts, as long as you rolled in the threads on the new bolts. I heard that you will screw up the thread sealer if you retorque the bolts if they move even a tiny little bit.

JSUP,
Heads are on. I took a month to get off my butt and go back out to the garage while its been cold. I got a good day this past weekend and went out there and spent some time rolling in the new ARP bolts and sinching them down.

As far as re-torqueing the heads after run-in, I'm kinda afraid to break the thread sealant as dan0617 said. ARP says nothing about re-torquing thier bolts. Anyone?

I'm running ARPs head bolts on the 388 I built last spring and didn't retorque them.

I did go over them all several times before buttoning up the engine for installation. I waited about 24 hours before I went through them for the last time. That allows the head gaskets to take any "set", just as with the intake manifold gaskets. I used a stretch gauge on the rod bolts rather than relying on torque; stretch is much more accurate.

Be careful about over-torquing the head bolts! Use the procedure and spec ARP recommends to prevent distorting the cylinder walls with too much torque. If you measure the bore diameter both before and with the heads are bolted on you'll see the walls move due to the head bolt torque, That's why blocks are bored and honed with torque plates in place. They'll measure out of round with no head bolted on, but round with the heads in place.

I use Permatex #2 thread sealant- that dark brown really gooey stuff - and because of how it works, I wasn't concerned about breaking any seal it provides.

I built the engine in Park Forest, Illinois and after a 100 miles or so of both street and shorts stints on the Interstate, I headed for Dallas. The only problem I've had since the build was a stuck closed thermostat a month or so after I arrived in TX. I went with a Fail-Safe model to prevent that problem in the future.

When the stat failed in the closed position, the engine got as hot at 260F before I was able to make it home. Even at that temp, no damage resulted. Even after a year from the stat failure, engine is still as tight as Dick's Hat Band.

Jake

Break-In: Moly rings seat almost instantly, but I did do a break-in procedure. I primed the hell out of the new engine, turning the crank every couple of minutes. Even after I no longer saw any signs of air being forced out, I kept priming.

Yep, changing oil frequently is what I did too. I followed Golen's recommendation and used Valvoline VR1 Racing Oil, 20W50; NOT synthetic. I cut open the first two oil filters during the oil changes just to see what's what, looking for any silver or copper glitter.

I also loaded and unloaded the engine many times. Doing that at idle won't get the job done; engine needs a load on it.

I drove the car onto the interstate, brought the speed up to around 50-60 MPH in 2nd gear (auto) using moderate throttle pressure, then took my foot off the gas and let the engine pull down to around 20 MPH. I did this many times.

Of course, you'll need to be in an area that's relatively free of traffic so as not to get rear-ended while doing 20 MPH on the interstate.

Watch your temp and pressure gauges like a HAWK until everything settles in.

This is just how I did mine.

Jake

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How long would you consider "settled in"?

FWIW, jake266 has the idea. when you load an new engine (and I don't mean killer load) the forces on the pistons/rings help clean the oil from the cylinder walls. Then when you back it down under load, it washes oil back onto the cylinders. Sort of a wet-dry-wet-dry effect. Helps the rings seat.

Watch the temp and oil gauges, look for leaks and enjoy.

The GM steel shim gaskets AND the Fel-Pro blue head gaskets do not need to be retorqued. Doing so will invite problems.

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I didn't do the bottom end. It's a stock 1990 L98. I used a Felpro 1010 gasket.

How long until I can relax, for the top end?

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I'd personally say that 500-1000 miles with no runs-drips-errors it's good to go...

Sorry, I thought you'd done the whole thing-- My Bad!

For just the top end-- it starts, it runs, it has no leaks, it's GOOD. Relax- have a beer.

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The bottom end only had 30K miles. Didn't see the point.

To me "settled" is when all the temps, pressures and idle become predictable and consistent. No code, no leaks and no flucuations from day to day.

Jake