Project "Payback"

[Vegas69]

I don't know why they external balance the 489. In my research most of the cast cranks are external balance in 4.25 stroke. I assume it's much easier to just balance the bob weights and use external balanced flywheel/balancer. I am very impressed with the engine as far as performance goes. I caught them during some growing pains and now paying the price for it. The rear main seal also has a small drip. I might as well dig in while I'm there. Now that I know it's two peice I get to pull the oil pan as well.

Frank...you are correct that mcleod makes a separate flywheel for Gen VI 454 and 502. Mcleod said the counter balance weight is the same but the placement is slightly different. I never dreamed I had a gen iv crank in this motor. Thanks for the words about the car.

[68protouring454]

i used scat 4130 crank and h beam end cap screw rods, 4.250 crank, 6.385 rod with wiseco forged piston.
the crank i got was external balance as well but there was a certain part number that was almost always too heavy and not light as its way cheaper to take weight out, then ass it.
hopefully you don't have any issues, the rear main will be fun enough. goodluck

[Vegas69]

Three hours later and it's all apart. Probably a half hour on a hoist.

Anyway here we go.

This is an interesting picture and what I believe to be the reason the improper flywheel didn't vibrate anywhere but that specific rpm range. The centerforce weights were definitely compensating.

[Vegas69]

The inside of the bellhousing has a ring around the inside. This is definitely throw out bearing grease.


The clutch, flywheel, and pressure plate couldn't look better. No oil penetration.

[Vegas69]

After three days of crawling around on the garage floor, I got it back together. I went with the proper gen iv centerforce billet steel flywheel. Nice piece. Of course I then had to remove the shims from my starter nose due to about .060 difference in nose to ring gear clearance difference from gen iv to vi. I did buy a real metal clutch alignment tool for like 20 bucks. The tranny went in so easy. I had it up and in in less than 10 minutes. Best 20 bucks I ever spent.


Well, it's smoother everywhere. But......I still have a vibration. Now it's only at 2800 rpm. Man is she a sweetheart everywhere else. I tried to feel a weight on the balancer but couldn't get my fingers in there. Next I need to verify it's got the correct balancer.

It gave me a chance to clean the bottom while I was under there. Changed the oil and it looked great, changed the tranny fluid and it looked fine as well. Seems things are breaking in nicely. Here are some photos of the bottom. Don't think I have posted many.

The guys at ATS did a fantastic job on my exhaust. Fits so nice and snug. Never has it touched anything in the road.

[Vegas69]

It will look good for a couple weeks.

[Vegas69]

[Spiffav8]

Still looks fairly clean....better get a few more miles on that sucker.

[Flash68]

Looks good under there man!

[waynieZ]

Hi Todd those headers firt very nice tucked way up. How did you make out with the interior guy?
Wayne