69 Camaro Engine Question

[Zaxx81]

My Dad has a 69 Camaro with a 427 ci engine that is not the original. The car is tubbed with drag racing rear wheels so it's not uncommon to not have the original engine.

Is there any definitive way to determine whether the original engine was a small-block or big-block? I'm not looking for a way to prove if it had a factory 427, just if it had a SB or BB.

[Rod]

the heater box on the firewall, the heater core tubes next to the fenderwell (center of heater box) its BB heater core tubes to the center of the car (edge of heater box) SB

[Zaxx81]

the heater box on the firewall, the heater core tubes next to the fenderwell (center of heater box) its BB heater core tubes to the center of the car (edge of heater box) SB

Is it easy to replace the heater box to fake? I don't think the previous owner was trying to fake a COPO because the car has Z-28 emblems on it. But it was originally an automatic so it can't be a Z-28 (plus it's X-11). The heater box has tubes in the middle.

[64impala]

run the vin

[63SW]

If its an X-11 car , it will be a SB car .
X-11 can be one of 2 models .
1) a BASE MODEL CAR WITH the Z-21 STYLE TRIM PACKAGE ( meaning - Chrome side louvers , rocker moldings , drip rail moldings , the headlight bezels will have the chrome ring around the outside edge , and the tail lights will have the chrome trim going up n down in the lens area )
Could be a 307 , 327 or a 350 car ... if a 350 car and was a factory 4 brl carb - Possibly a LM-1 CAR.
2) a SS-350 Model and can be an AUTOMATIC or a 4Speed Car.. 10 bolt is also a possibility. but i think should me a multi leaf car ..( not 100 % sure on the leaf spring fact tho )

Hope that helps.

PS , IF it had a original BB in it , it should have a plate welded to the side of the rear frame rail on the DR side just behind the rear center of the tire . THIS CAN ALSO BE ADDED and ONLY a $5 part but was for the dual exhaust hanger . .

if factory paint , possibly look for the rear tail panel to be SEMI FLAT BLACK .

Look at pics on CAMARO.ORG - might help.
copo's and ZL1s werent blacked out to my knowledge tho.