1967, L89 Aluminum heads: painted or natural finish?

[Kit D.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

Kit -

The '67 JG covers it - L-88 has painted heads and valve covers, L-89 has natural aluminum unpainted heads and chrome valve covers.

Aha! As I expected. Thank you for settling this, Mr. John. My judging manual is back in a storage unit!

Kit

[Kit D.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

I love this Forum. Great resource where people who know can share their knowledge with the rest of us.

Kit

[Joe L.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

Another interesting fact: there were TWO versions of the right side chrome valve cover used for 1967 L-89. One version had a welded-on bracket for the mixture control valve used with K-19-equipped cars. The other had no such bracket for non-K-19 cars. With only 16 1967 L-89's ever built, can you imagine how few were probably shipped to California? California was, of course, a big market for Corvettes but based upon the TOTAL number of K-19 cars built for 1967 (2,573) versus the total number of Corvettes built that year (22,940), we could estimate that about 11% of the Corvettes built were shipped to California. So, that would mean that about 2 L-89's were probably shipped to California. Nevertheless, the right side valve cover for those 2 cars was once available in SERVICE. Years ago I purchased an NOS example of this valve cover. I expect that there were a lot more covers manufactured for SERVICE than were ever used in PRODUCTION. I can't see a lot of these being once sold to folks that were trying to "dress up" their non chrome valve cover 1967 big blocks. Those folks were almost sure to have unceremoniously removed the K-19 system so they would not want a right side valve cover with the bracket for the mixture control ("diverter") valve.

[Joe L.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

So, why did 1967 L-89 have unpainted aluminum heads while the L-88 had painted heads. Well, I surmise it was because the L-89 was a STREET engine and folks paying the premium for the aluminum heads would probably want to have them visible. The L-88 was an OFF-ROAD engine. Folks buying an L-88 probably didn't care about how the engine appeared and Chevrolet probably didn't want to do anything to entice folks to buy them for the street. So, painting the L-88 heads served all purposes.

What about the L-89's chrome valve covers? I expect the biggest reason for using them was to avoid the need to laboriously mask off the heads OR paint the valve covers off the engine to install after engine painting. At the same time, they "dressed up" the extra-cost engine and "accentuated and complemented" the aluminum heads. The L-88 was simply painted in the same manner as the vast majority of other 1967 big blocks.

For 1968 and 1969, the years that the VAST majority of aluminum head big blocks ever produced were manufactured and the years that ALL big block intake manifolds were aluminum, Chevrolet installed chrome valve covers on ALL Corvette big blocks.

The only year that painted valve covers were ever installed on an aluminum head big block was 1971 for the LS-6. I don't know whether those engines had the valve covers painted off the engine or whether some sort of masking or mask was used.

Discounting the handful of 1960 small blocks with aluminum heads, small blocks received aluminum heads for the first time for the 1986 model year. However, by that time engines were component painted so that completely solved the problem of leaving bare the aluminum heads.

[Bill M.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

So, why did 1967 L-89 have unpainted aluminum heads while the L-88 had painted heads. Well, I surmise it was because the L-89 was a STREET engine and folks paying the premium for the aluminum heads would probably want to have them visible. The L-88 was an OFF-ROAD engine.

My guess: Tonawanda process was much simpler for the L-88 if the heads were painted.

[Al P.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

Kit -

The '67 JG covers it - L-88 has painted heads and valve covers, L-89 has natural aluminum unpainted heads and chrome valve covers.

Rodger that!

[Mark D.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

I would love to know how in the world the L89 motors were painted in 67 (and 68/69 also). Think about it, the manifolds are painted but the heads are not? That must've been one convoluted process of prepping the job for paint. I can't think of a mask that would allow the exhaust manifold(s) to be painted while the head(s) weren't. 68/69 (chrome valve covers) would be even more intricate and the the most psychedelic prep of all must've been the 71 LS6 motors.

Clem is right, Harwood's car is no doubt the real deal and well documented at that. Harwood is a great guy and very generous with his memories of his silver L89.

[Mark D.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

Harwood's car sounding good...

[Michael H.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

I would love to know how in the world the L89 motors were painted in 67 (and 68/69 also). Think about it, the manifolds are painted but the heads are not?

Mark,

I doubt the exhaust manifolds were painted at all on the upper side near the head on aluminum head L89 engines. The manifolds were not an intentional target on any big block but received a coat of orange because "they were there", directly in the line of fire for the valve covers, heads and block on engines with iron heads.
The lower section would have been painted though.

[Mark D.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

Cranky,

That makes sense. Here is how the paint looks around the heads of Harwood's L89 right now (car is restored) and I'm thinking this wouldn't have been typical. It would be as you described and that paint would've burned off quickly.

Mark

[Steve B.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

Cranky,

That makes sense. Here is how the paint looks around the heads of Harwood's L89 right now (car is restored) and I'm thinking this wouldn't have been typical. It would be as you described and that paint would've burned off quickly.

Mark

Mark, I have often wondered the same thing. I know of two low mileage unrestored aluminum head cars (one a 12k mile 68 L89 and a 20k mile 69 L88) that have faint remains of orange paint on the top of the manifolds. Both cars have never been apart.

[Wayne M.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

Mark,

I doubt the exhaust manifolds were painted at all on the upper side near the head on aluminum head L89 engines. The manifolds were not an intentional target on any big block but received a coat of orange because "they were there", directly in the line of fire for the valve covers, heads and block on engines with iron heads.
The lower section would have been painted though.

Agree 100% -- no reason that the top of the exh manif should have been in the firing line of a paint gun. I bolted an 828 RH exh. manif to an 842 aluminum head (mounted on a '961' block). LOTS of room to spray to the top of the iron block from under the exh.manif. In fact, the top edge of the block is 4_1/2" down from the A.I.R. plugs, and the gap is about 3 fingers wide and one thick. Chance of getting any orange on the block by spraying from above is nil and none .

IMHO, the ends of the Al heads, at the iron block interface and the intake on the top of the timing chain cover would be the real masking challenges.

[Joe L.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

Agree 100% -- no reason that the top of the exh manif should have been in the firing line of a paint gun. I bolted an 828 RH exh. manif to an 842 aluminum head (mounted on a '961' block). LOTS of room to spray to the top of the iron block from under the exh.manif. In fact, the top edge of the block is 4_1/2" down from the A.I.R. plugs, and the gap is about 3 fingers wide and one thick. Chance of getting any orange on the block by spraying from above is nil and none .

IMHO, the ends of the Al heads, at the iron block interface and the intake on the top of the timing chain cover would be the real masking challenges.

Wayne-----


Well, fortunately for them, the folks at Tonawanda did not have to do it very often.

[Patrick B.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

Sorry to stray slightly from the subject, but I thought those with L89 knowledge might be reading. I am interested in putting some 392 L89 heads on my 67 L71. With those heads the engine weight would closer to a small block than to the L71. I cannot find any reference in my parts books to different front springs for the L89. Did it use the regular big block front springs? small block springs or something unique? If they used the big block springs, did they sit up noticably high in the front?

[Joe L.]

Re: 1967, L89 Aluminum heads: painted or natural finish?

Sorry to stray slightly from the subject, but I thought those with L89 knowledge might be reading. I am interested in putting some 392 L89 heads on my 67 L71. With those heads the engine weight would closer to a small block than to the L71. I cannot find any reference in my parts books to different front springs for the L89. Did it use the regular big block front springs? small block springs or something unique? If they used the big block springs, did they sit up noticably high in the front?

Patrick-----


1967 L-89 used the same front spring as other big blocks without C-60. That spring was GM #3888250.