71 454 (LS5) heads on 72?

[Mike E.]

Just pulled the original valve covers off an early 72 built October 71. Block is cast H 30 71, and assembled September 9. T0909. Heads are cast F 28 71 and G 6 71. No issues with any of that. Issue is that the casting number is 3993820, which the JG indicates is for 71 only. Any others with that kind of an issue? This car has the original carb, intake alternator, air cleaner, tranny, rear, exhaust manifolds, etc. it has never been owned (two families) that cared anything about numbers.

[Ronald L.]

Re: 71 454 (LS5) heads on 72?

Early September build, its called run out the old stock.

[Tom L.]

Re: 71 454 (LS5) heads on 72?

I also have an early October LS5. Both heads were cast on the same day at the same time (according to the little clock symol cast into them) in the month of September and have the correct casting numbers. I don't have the specifics here but can get them if you'd like.

[Dick W.]

Re: 71 454 (LS5) heads on 72?

I believe the combustion chamber changed from closed chamber in '71 to open chamber in '72.

[Patrick B.]

Re: 71 454 (LS5) heads on 72?

The 3993820 was open chamber with 113 cc combustion chambers. The '72 head 3999241 was also 113 cc and described by Alan Colvin as similar to 3993820. I'm going with the "run out the old stock" theory.

[Mike E.]

Re: 71 454 (LS5) heads on 72?

I fully understand the run out the old stock. I guess I didn't ask clearly. This is a mid-October car (43xx). Nothing is reflected about this in the 70-72 JG, nor is there anything in the archives on this head number showing up in 72. Having written a number of articles for the Restorer on component dating, the "is this documented or do I need to document it?" tape starts playing in my head. Seems odd if all of a sudden one mid-October car would demonstrate this. Are there earlier 72 ls5 cars that have been seen with these heads?

[Dick W.]

Re: 71 454 (LS5) heads on 72?

The 3993820 was open chamber with 113 cc combustion chambers. The '72 head 3999241 was also 113 cc and described by Alan Colvin as similar to 3993820. I'm going with the "run out the old stock" theory.

OK, I can buy the old stock theory. During that era inventory was not "FIFO" first in, first out, but rather "LIFO" last in first out, in a lot of cases.

[Paul O.]

Re: 71 454 (LS5) heads on 72?

Mike

My opinion would be document what is installed (if it seems to be never disassembled) the Judging Guide is a living document. You need to document this so we have this in the data base for the next revision if we can document other LS5 around this time frame having the same setup. There is such a small segment of member on the discussion board compared to our actual membership of the NCRS this needs to be spread across the membership for more input.

[Patrick B.]

Re: 71 454 (LS5) heads on 72?

OK, I can buy the old stock theory. During that era inventory was not "FIFO" first in, first out, but rather "LIFO" last in first out, in a lot of cases.

"LIFO" explains an early Sept engine in a mid-October car. Heads made two months before the engine build date is pretty typical for big blocks. I'll bet most if not all August 71 built 72 454's have 820 heads. Does anyone have an early dated 241 head? The chance of a very early 72 engine just happening to acquire very late 71 heads outside of the factory is very slim especially when there are no obvious differences in the heads except casting number. We need someone with an August dated 72 454 to take off the valve covers and have a look.

[Mike E.]

Re: 71 454 (LS5) heads on 72?

OK, I can buy the old stock theory. During that era inventory was not "FIFO" first in, first out, but rather "LIFO" last in first out, in a lot of cases.

And this would have been "FILO".

[Tom L.]

Re: 71 454 (LS5) heads on 72?

Mike, based on the vin info you've provided our cars aren't more than two or three days apart. The heads on my car are the correct 241 casting dated only 1 day before the c3 registry's brithday calculator estimates. Unfortunately they are sitting on a CE block. Since the manifolds, intake and exhaust are correctly numberred and dated I've always assumed they were original to the car and only the block was replaced in June of '72 (casting date on the block). What reinforced my asssumption was that someone re-stamped the engine code on the stamp pad before the heads were placed on the block, I know this because part of that stamping is covered by the head.

I hopes this info helps you but I wonder; Is it realistic that the heads were cast only a day or two before the build date??

[John H.]

Re: 71 454 (LS5) heads on 72?

Is it realistic that the heads were cast only a day or two before the build date??

Lynn -

Which build date - engine or car?

[Monte M.]

Re: 71 454 (LS5) heads on 72?

Lynn,
I am assuming you are talking about the heads being cast a day or two before the actual build date of the engine.

I have actually had two 72 454 cars over the years. I stole a few parts off the second one I needed before I ended up selling it for a $900.00 profit. Sometimes things just work out. The one I have now I have had a very long time. One of the heads has a casting date that is only one day before the build date of the engine. For that to actually happen, I think the engine builder may have stamped the wrong date on the front pad of the block, or the casting date was wrong when they cast it.

It just seems like a lot of work to break the head out of it mold, get it cooled, get it to the valve grinding machine/bench, get it over to the engine assembly area and get it bolted to an engine. It sounds crazy, but I have no question that these are the heads that came on the car.

Just thought I would throw that out there for a little food for thought. If it was a day or two before the actual build date of the car, that would be suspicious.

Good to hear from you Lynn. Hope all is well.

Monte

[Patrick B.]

Re: 71 454 (LS5) heads on 72?

Mike, based on the vin info you've provided our cars aren't more than two or three days apart. The heads on my car are the correct 241 casting dated only 1 day before the c3 registry's brithday calculator estimates. Unfortunately they are sitting on a CE block. Since the manifolds, intake and exhaust are correctly numberred and dated I've always assumed they were original to the car and only the block was replaced in June of '72 (casting date on the block). What reinforced my asssumption was that someone re-stamped the engine code on the stamp pad before the heads were placed on the block, I know this because part of that stamping is covered by the head.

I hopes this info helps you but I wonder; Is it realistic that the heads were cast only a day or two before the build date??

It sounds like your 241 heads were cast in early to mid October. That still leaves open the question whether 241 heads were being cast in August which would be necessary to make them common on early Sept engines like Mike's.

[Terry M.]

Re: 71 454 (LS5) heads on 72?

Lynn,
I am assuming you are talking about the heads being cast a day or two before the actual build date of the engine.

I have actually had two 72 454 cars over the years. I stole a few parts off the second one I needed before I ended up selling it for a $900.00 profit. Sometimes things just work out. The one I have now I have had a very long time. One of the heads has a casting date that is only one day before the build date of the engine. For that to actually happen, I think the engine builder may have stamped the wrong date on the front pad of the block, or the casting date was wrong when they cast it.

It just seems like a lot of work to break the head out of it mold, get it cooled, get it to the valve grinding machine/bench, get it over to the engine assembly area and get it bolted to an engine. It sounds crazy, but I have no question that these are the heads that came on the car.

Just thought I would throw that out there for a little food for thought. If it was a day or two before the actual build date of the car, that would be suspicious.

Good to hear from you Lynn. Hope all is well.

Monte

Monte,
If you ever saw the Tonawanda engine facility you would not question that. The expression S)&t through a tin horn comes to mind. Flint was even faster.