[poncho-mike]

I've got a number of 428s that I took apart and stored the pieces and parts in different locations. In the mid-1980s I found a 1969 428HO 4-spd Grand Prix in rough shape. The car was mostly complete, but the tranny was gone, and the motor was still in it. I was able to talk the owner into selling me the engine and some other parts.

The motor consisted of a SR 428 4-bolt block, #48 heads, and the long branch manifolds. The dates don't seem to line up with what I would expect. The exhaust manifolds were dated early April 1969. I still have a 1111952 distributor dated in late March, which I think is the original distributor for that engine. The 428 4-bolt SR block is dated E279.

What is confusing me is how close the SR block date is to the other engine parts that were on the car. I sold the heads long ago, but I think they were dated late March as well. I would expect a SR block to be dated at least six months or more after the surviving components dates.

Any thoughts on this?

Mike

[mgarblik]

A very early engine failure requiring a SR block to return to service. I had a friend who purchased a 428 HO GP new in 69 expressly for drag racing. Low option car to keep it light. He killed the engine by over reving it and tossed the rods out the side of the block. It got a SR block at the dealer and was a couple months old. So it's possible. Less likely on 428's than 400's IMO. Because they were installed in 67-69 full size cars only and few were raced in full size bodies. But plenty were transplanted into GTO's, Tempests and Firebirds when the big boost in torque was discovered and enjoyed.

[Rocky Rotella]

I'd agree with above. Likely an early failure.

If possible, can you share pics of the casting number, SR number, casting date, and if the pan is off, the main caps?

[hawkins69]

My 69 GP 428 HO 4-speed car was built Nov 68. Was a special order car from Montana. In April 69 at 4K miles, suffered engine failure. Engine short block was replaced by dealer under warranty. That block is a SR block and is still with the car. I want to say it’s cast Jan 69 but I’ll double check

[poncho-mike]

I'm not entirely clear on how the SR block situation worked. I was under the impression that the dealer didn't keep SR blocks in their inventory. So when a car came in that needed a replacement block, the dealership had to order it. I had a friend who worked as a mechanic for a Pontiac dealership from about 1965 until 1974, and that is what he told me. I got several 4-bolt blocks from him because he would save any 4-bolt blocks that were replaced under warranty.

Rocky, it won't be easy to get the information you're looking for. When I got an engine I planned to keep, I stripped the heads, distributor, oil pan, and oil pump off. I greased any visible metal with white lithium grease or painted axle grease on with a brush. I then wrapped it in plastic wrap, and double bagged it. I generally wrote the engine, code, standard or over-bore, and noted condition on white tape. When somebody wants to buy one, we pull it out and cut open the bag to verify bore and codes. If I do sell it and the buyer wants to inspect, I'll record the info.

I'm thinking I might be better off selling the distributor for a Ram III Firebird, which I think is the same p/n.

[mr67gp]

I pulled an SR 428HO from a '68 Bonneville 'vert years ago. I recall it was an early 70s cast date on the replacement block, so not sure how that bock made it into that car. No code stamp or S/N stamped on the front of the block. SR castings were probably made during production, and apparently long after.

[poncho-mike]

The question I still have is whether most dealers kept service blocks on hand for when engines failed, or if they ordered them after they had a need.

[mgarblik]

Originally Posted by poncho-mike

The question I still have is whether most dealers kept service blocks on hand for when engines failed, or if they ordered them after they had a need.

I can give you a partial answer. I think it depended on the size of the dealer and the inventory they wished to have on hand. The Pontiac dealer I worked at was "mid sized" We had about 20 service bays. Our parts department kept some "fast moving" SR blocks in stock. In the late 70's, early 80's, our dealer had 3-4 Olds 350 diesel long blocks in stock due to massive failures. Also they stocked SR long blocks for Pontiac T-grands, (Pontiac Chevettes), when they were breaking crankshaft noses off at an astounding rate. I do remember a few Pontiac V-8 blocks in crates sitting in the parts area from time to time. Later, when teaching for the GM ASEP program in the early 1990's, most Chevy dealers had 2-3 SR blocks in stock for the Chevy 3.1 V-6. They had thousands of them crack the block right through the lifter valley, front to rear. One dealer I called on had a "super tech" who was so fast he could remove and install a SR 3.1 L block in a Corsica or Lumiuna in 1 day, about 8 hours. He was doing 2-3 a week for a year. Specifically for your block: A 428 was limited production, only 3 years and only full size cars. It is my "guess" that only a very large dealer or one that specialized in performance cars like Royal, Knaffel or similar would stock SR 428 blocks.

[mr67gp]

What Mike said - no good economic reason to inventory SR blocks unless there was a chronic failure pattern with that engine family. Order as needed, AFTER warranty claim is approved for the SR engine swap. Pretty sure then as now, warranty work is done at cost by the dealership for reimbursement by the manufacturer. It actually costs the dealership money to do that, since actual profit generating work is displaced by the warranty work.

[joegpho]

How did it work then for engines to get a block code under warranty?
For this example, somewhere (I cannot recall where) I saw that there were 142 428 HO manual transmission blocks cast in 1969 - code WL. But - there were only 119 GPs with that engine. Does this mean that 23 engines were assembled and stamped at the engine plant - either due to warranty replacement requests or projected warranty replacements?

[north]

Could also be that they overestimated need for the engine and ended the model year with a few leftovers.

[Bird_collector]

Originally Posted by poncho-mike

I'm thinking I might be better off selling the distributor for a Ram III Firebird, which I think is the same p/n.

I'd be interested in buying this distributor if you wish to sell it. PM me.


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