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#1
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The 291 heads are considered to be the correct cylinder heads but was it possible to have 840s?
Thanks Andrew 1970 Camaro SS/RS L78 4spd 1970 Camaro SS396 10.5 tire |
#2
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Andrew, Asking that your 70 L-78 be part of the registry
that Mike Steitz (aka Thnder) at www.nastyz28.com has. I'm seeking ONE picture of original eng compartment to support my opinion on style of drivers side smog tube routing. NO known 70 L-78 survivor, NO known 70' period pictures, or magazine articles
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Chuck Sharin [email protected] Auburn,WA (30 miles South of Seattle) 70 Camaro R/S Z-28, L-78, R/S SS 69 Camaro COPO "recreation" |
#3
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I believe that to date all we have seen are 291s on L78 Camaros. Like Chuck said, Mike Steitz would be the guy to contact as he holds the info for the L78 Registry.
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1969 Z28 1972 Corvette |
#4
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I would figure that since the 70 Camaro (actually 70 1/2) was a very late release, they would have been done with the leftover 840's by then.? My .02
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70 L78 Nova Fathom Blue,Bench, 4spd, F41, 3:55 71 Porsche 911 Targa |
#5
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Sorry Chuck, I can't help you with an under the hood pix. I will keep my eyes open. The car is already in the registry. I just emailed Mike, I never thought of him.
Thanks Guys! ![]() Andrew 1970 Camaro SS RS L78 4spd 1970 Camaro SS396 10.5 tire |
#6
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my late 69 L-78 nova had one 291 and one 840....
my 70 L-78 camaro had 291's, i believe the camaro was an early car, the heads were dec-69 and jan 70 |
#7
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My L-78 was probably in the first Norwood group, 01C.
291 Heads Here, on a Nov assembled engine Would be interesting to hear from 70 L-78 and LS-6 Chevelle owners re: 840 heads ????
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Chuck Sharin [email protected] Auburn,WA (30 miles South of Seattle) 70 Camaro R/S Z-28, L-78, R/S SS 69 Camaro COPO "recreation" |
#8
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The biggest difference between those two heads is that the the exhaust valve diameters are larger on the #291 (1.88 Diam.) The #840 still had the 1.72 exhaust valves. Now somebody enlighten me as to what kind of seat is on the spark plug of the 1969 #840 heads. I thought that 1970 #291's used a short-reach, tapered seat. I've heard of several late-1969 L78 cars using a #291 cylinder head on one side and an #840 head on the other. That points towards the #840 head being phased out even before the 1969 model year was over so I would think that ALL 1970 L78 and LS6 engines used the #291's. Especially the late introduced 1970.5 Camaros.
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1962 Biscayne O-21669 MKIV/M-22 1962 Bel Air Sport Coupe 409/1,000 |
#9
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I agree with you Mark. I have seen a lot of June of 1969 built 291 heads. That means some of the late '69 cars could have gotten 291's when they ran out of the 840's.
That's a good question. If each head took a different plug, you would have to get 2 sets of plugs. ![]() Kurt |
#10
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I have 1 840 head that takes the newer plugs? Would that be for that NOVA application with the mixed heads?
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