[JeffersonC]

Just searching around ebay to see what prices go for on the 492s as I have a pair and came across these Crane Cams 1970 ones. Anyone ever heard of these? The ports look huge! Worth picking up? The guy is close to me.

http://cgi.ebay.com/ebaymotors/Chevr...028191001r4908

[brian oneil]

"The best small-block Corvette heads include the following:492 (double hump)-The prototypical double-hump, cast-iron, small-block head is casting number 3991492. The double hump or "camel hump" casting marks can be found on a variety of small-block iron heads and designate a high-performance casting. Many heads with the double-hump mark were installed on fuel-injected Corvette engines, dating back to 1960. As a result, 492 and other double-hump castings are routinely referred to as a fuel-injection or fuelie heads, even though they were also used on the original LT-1 and the 302ci Z/28 Camaro engine. Common features include 2.02/1.60-inch valves, 64cc combustion chambers, and 160cc intake runner volume. As part number 3987376, this head featured screw-in rocker arm studs and pushrod guide plates. But as part number 3958603 (discontinued in 1991), a 492 casting had pressed-in studs and was machined for 1.94/1.50-inch intake/exhaust valves."
By Dave Emanuel

As long as they are not cracked, they may be worth the money. Dart Iron Eagle may be just as cheap once all the machine work is done and all parts are bought. Kinda hard for 70's tech to outflow modern design.

[JeffersonC]

Of course it would be cheaper to buy a new set of heads and be done, but to have a probably limited run of classic performace heads would be sweet to have/rebuild.
Big Dave or any of you guys ever heard of these?

[Big Dave]

Those heads have been professionally ported but they will need a valve job as at least one aftermarket hardened seat has fallen out already due to a bent or broken valve (nick in the chamber next to the missing valve seat were the valve head kissed the piston and broke off to hit the head). They have probably been angle cut at least once which reduces any chance of milling them flat if they are warped, it also promotes cracking in between the two holes at the spark plug quench supply as the metal is thin and unsupported (so have them magnafluxed for cracks).

So far you are paying 1/3 the price of a new aftermarket head (which can be machined to have a double hump front ID pad to attempt to disguise your aftermarket head) plus shipping. You need to pay to have them magnafluxed a new seat and a valve job and at least one guide will need replacing so I would say you are already talking 4/5 the way to an aftermarket head for a used head that will not flow as much and may still be unusable because of undetected cracks. That added to the fact that there is three days of bidding to go and sniper software could drive it above your max at the last second (making you miss out on the Halloween special on at least two aftermarket head manufactures who are offering Spook-Tacular buys on heads right now.

Big Dave

[brian oneil]

Originally Posted by Big Dave

drive it above your max at the last second making you miss out on the Halloween special on at least two aftermarket head manufactures who are offering Spook-Tacular buys on heads right now.

Big Dave

Good one Dave

[Jackel]

If you win the bid at your calculated price it would be a nice head for a period correct motor build. I think the 100 HP extra claim seems to be exaggerated. If you have the spare coin, it would be a great project for you to document, maybe even do a article based around the build. Jackel

[SHIFTY4]

i've got a set of Humpers here at home... professionally done in the early '80's. a set of 291's. ported/polished, cc'd to 68, 1.94's & 1.625's with guide plates & studs.

[Jackel]

Jefferson, did you buy the heads? Jackel

[JeffersonC]

No I didn't unfortunately they came up just under 400$ which was a little too much for me

[Jackel]

Additional info from the Camaro Forum on these heads....Looks like they would be great on a stock looking, restored small block SS. Jackel

http://www.camaros.net/forums/archiv.../t-169430.html

[Big Dave]

If you are just looking for double humps for the look and would prefer a more modern computer aided design on a head the double camel hump ID casting mark can be machined into a more modern head with a CNC lathe. A cheap Sportsman II Dart head will out perform the '492 heads hands down and is often cheaper when found used.

Just to remind you how old this head design is check out the DA's on these two guys working on the first iteration of Project-X back when it was an ARGOS car not Pertersen publishing. Note T-shirts were considered under wear back then.



Big Dave

[brian oneil]

Yeah look at the date on that magazine too. I was only a year old

[Jackel]

I was being drafted for service in the military. Nice shirt to work on a car though. Gives these guys a nice clean image that dad would approve of. Jack