1969 Camaro Heater box question
 

Ecklers sells the following heater box cover that is show correct. I always thought the only difference in the small block and big block cover was the center punched holes. This box and a square indentation that the small block doesn't. Is this correct?

No.

Thank you.

JMHO, but this is a really dumb decision by GM to use two different heater box covers and heater cores.

Once they figured out the original small block configuration was going to interfere with the BB install, they should have just superceded and made all of them with the revised heater core/cover. No reason you can't use that one in either application. I have no idea of the additional cost to maintain and install four different parts, but there had to be some cost involved.

There's more than four different parts.

1969 list:

Frame brackets for the motor mounts, manual trans crossmember, auto trans crossmember, clutch cross-shaft, pedal return spring & extension, shifter mounting brackets & rods, radiator & shroud, heater core, L34/L35 tachometer, male end of throttle rod, power steering pump reservoir, gauge oil pressure line, battery cables, front exhaust pipes, front springs and possibly shocks, vacuum pipe to brake booster [2 #s L72/L78 different]. A/C big blocks had an additional radiator shroud mounted under the core support.

The auto trans kickdown mechanism for a BB/auto is completely different than SB. The L72/L78 used a different switch mounting bracket than the L34/35.

I get there are a lot of other parts that were necessary. Just don't know why they couldn't use the same heater core and cover.

GM wasted a lot of time, money, and effort on stuff like this. Here’s an example that makes me shake my head and ask WTFO? 1968 Camaro Rally Sport option. Look at all the possible vacuum fittings…4 for the inline 6 and 8 different ones for the V8. Would a rubber plug be cheaper? Or a non drilled/filled port?
And here’s another. My car has a 6 cylinder, AC, PS, and an M35, so it gets the 796 alternator, not the 817 as called out in the C60 section in the AIM. THE 817 would be for a manual transmission right? But I also have PS, so it gets the 817 as called out in the AIM in the N40 section for you guessed it—M35. This is where I SMFH because there’s no communication. I digress.
And if anyone has or knows of a 1100817 alternator, please contact me. It’s a 61 amp. Have a great Sunday peeps.

Short answer, the frame brackets offset a BB to the right to clear the steering gear. That interferes with the heater hose connections.

Measured at the rear block surface, a BB is also positioned further forward than a SB.

Since the BB was developed long before Camaro came on the market, it would have been a simple matter to design the chassis to accommodate both engines, using the same parts.

My guess, Chevrolet did not intend to offer it in the Camaro. Fall '66, Ford took some buzz off the new Camaro by offering the 390 in the '67 Mustang. Had to respond.

Question for the Firebird guys: Does the 326/350 directly interchange with the 400?

I believe the 326 thru 455 all interchange

Yes, they all used the same block.