Engine of my RQB2273

[Brooks Barnes]

Can anyone onboard tell me how I can detrermine the size of engine ( 400, 327 or 350 ) my 1975 RQB2273 came with originaly?

[Gunslinger]

Your car came originally with a 400 c.i. engine.  It should be a 4-barrel.  

[Brooks Barnes]

thank you sir

[mfg]

As an aside… 400 CI small block Chevy engines are becoming quite valuable, with some folks considering the two bolt main cap version of the engine superior in strength to the four bolt version.

[plwindish]

Geez, I knew there was a reason why I kept the 400 in my '76 (RQB-2392) through many overheating issues in traffic going to meets, two engine rebuilds in '11 and again in '17, though the rebuilds were for different reasons.  The '11 rebuild was to modernize the engine with new pistons, roller cam, roller lifters, aluminum intake, performer carb, block hugger ceramic coated headers as well as work done on the heads passages for better intake and exhaust air passage.  The work resulted in an engine dyno stand performance of 360 horsepower and 400 foot pounds torque. A rebuilt 200R4 AOD transmission was also installed after the engine was reinstalled in the car making for a nice highway cruising Avanti until traveling to Colorado Springs in '13 for a Meet where car completely fell on its face after being in the altitude for a week, needing to be shipped back to Illinois to get straightened back out, carb, spark plug wires and distributor were all suspect. 

The '17 rebuild was due to a decision to go to an MSD EFI and my mechanic suspected and found a cracked head with some cylinder damage, making it necessary for the second rebuild. The motor is now a 408 with only the block, crank, fan and oil pan original engine parts. The EFI set up is all MSD with the EFI kit, Ignition box, and distributor. This time the dyno test stand readings were 522 lbs of torque @ 4400 RPM's and 471.5 HP @ 5400 RPM's. BTW, with  the exception of an inline electric fuel pump failing within the first year, there have been no issues with the EFI system on the car since installation in August 2017. I put the car in storage around November every year, disconnect the battery, cover the car and sometime in April uncover it, reconnect the battery and it starts right up to drive home.

Dart aluminum heads, a re-cored radiator and 160 thermostat seem to have taken care of the over-heating issues. The nearly 600 mile round trip to Livonia MI for the AOAI Meet September saw the AC working comfortably the entire trip, the temperature gauge staying in the 160-185 range except in a back up on 80/94 in Illinois on the return trip where the temp got in the 195 range before I turned off the AC and opened windows and vents. Economy wise, with the cruise set at 74-75 when feasible, 20.94 going up and 21.13 coming back. 

I got the car in January '11 to drive to AOAI and SDC Meets while heading toward retirement in '17.  Since the first rebuild I've put just over 54000 miles on the car.  Its been to the East coast 3 times and the West coast once as well as all over the Midwest from our home in Illinois.  The car has had pretty much a frame on restoration over the years I have had the car with the last major project being the interior vinyl, carpeting and seat belts being completed in early '23.

[mfg]

That color… That interior…That engine….

WOW!!!!!!!!!!!  X2 !!!!!!!!!

[mfg]

And those wheels!!!!!!!!!!!