When I was about your age I owned a 1966 Belvedere II Convertible, it was an original Daffodil Yellow (pale yellow) and an original 383 Comando (pretty rare car actually, wish I still had it). The previous owner put those stupid deep dish chrome wheels on it with bolt in wire baskets and 60 series BGF's all around. The original engine was WAY tired and the paint was faded all topped off with a silver replacement drivers door. As you can imagine, not much of a threat to look at it and it was REALLY quite sounding with Hemi mufflers and a full dual exhaust.
Long story short, I blew the 383 up one day (on purpose but that's another story) and replaced it with a super low mile 440 out of the local wrecking yard (only $150.00 in 1981 with 10 to choose from, ah those were the days!). It was a complete bolt in deal, all I did was add a new carb and had the exhaust welded up for the HP exhaust manifolds and painted the entire engine factory
Turquoise Blue. The car had a 3:55 Sure Grip and was an absalute monster as compared to the tired 383 that it once had, but it was still quiet and a "sleeper" for sure, although I never raced it for a time slip I'd say the car was probably a high 13 second/low 14 second car which is all it took to beat most cars you'd actually meet on the street back then.
The next weekend I went out to the local illegal street racing drags which was held outside of town at an old frontage road (This was in Vancouver Washington). There were at least 50 cars lined up to do battle, (and although I don't promote street racing anymore, back then it was allot of fun). I had my chance against a couple cars that night, the first was a green with orange flame job 69 Chevelle running a loud small block combo, I beat him so bad it he was done before I even put it into 3rd (Automatic). The next car was a 66 Mustang (either an original Shelby or a very nice clone). It was blue with white stripes, all kinds of chrome under the hood, Cobra valve covers, you know, the whole Shelby glitzy dress up package, etc. Overall a VERY nice car. That car was a 4 speed car and the owner was a real punk, mouthing off to everyone about how fast his car was (perfect example of a spoiled "silver sthingy" kid for sure).
Anyway, I really thought he would beat me so I just lined up and hit the gas......I WASTED him buy 4-5 car lengths! We returned to the start and he was even louder now, telling everyone how he'd missed a shift and how I cheated and jumped the start, etc. (He would have made a perfect "Pinks" contestant) so we agreed to do it again. This time I beat him even worse! LOL! It was great! ...But nothing, and I mean NOTHING was better than the look on his face when I popped my hood to reveal my "Stock 383"
looking all inocent in it's bland light blue paint job and running so smooth you could barely hear it.
Moral of the story? Sleepers (even if just a sleeper engine) are cool in my book