Our 69 Yenko Chevelle restoration

[m22mike]

I wish I could do more for you and Annie, it's just awesome that this car is in your hands and not another huge collection.
And thanks for the thread, learned a bunch, and thanks for sharing.

Mike

[VintageMusclecar]

Originally Posted by SS427

The engine was rebuilt by our own Eric Jackson (Vintage Muscle Car Parts) who did a great job pulling 478 hp at 5500 rpm and 472 ft pounds of torque at, get this, 3500 rpm. This thing will have some power though I am told by a certain young lady that I will never find out just how much. We made absolutely no power adders on this engine and it was rebuilt stock. Stock bore, crank, rods, pistons, a nostalgic cam with factory specs, stock heads and intake. Only the carb and distributor was blueprinted. After completion Eric worked with "Ohio George" Montgomery and dynoed the engine. Kudos to Eric for getting this thing done and with that much power. In comparison, our LS6 454 engines (that I have rebuilt locally) are generally .040-.060 over bore and otherwise stock and pull 475-498 horse so I am very pleased with the results. Correct me on any of this information Eric if I am listing it incorrectly.

Rick;

Sorry for the delayed response.


The engine is .030" over--strangely enough, when we checked the bores on initial examination, they were actually pretty straight--but they were just over .002" oversize, which would've left .0075"+ piston to wall clearance with the original pistons. That would've rattled like hell when it was cold which obviously wouldn't do, so we had to go .030" with new pistons to get the wall clearance where we wanted it.


The heads are bone stock with 2.19/1.72 valves and a 3 angle valve job, that's it.



The cam is pretty close to the factory 143, but with a little less duration and a touch more lift (I never divulge exact cam specs, that's up to Rick if he wants to reveal them). The LSA is fairly close to stock, and it idles much as the 143 cam would.



Since this is a 4 speed car with a 4.10 gear, Rick & I initially discussed spicing things up just a little, but since this car will never be pounded on and hero dyno #'s weren't part of the plan, I decided to try to pick up as much low end and mid-range torque as I could w/o sacrificing anything up top. I'm pretty happy with the results, esp. considering it surpassed my goals (460 lb.ft, 475 HP) on the very first pull. FWIW, coolant temp was 180° and total timing was 36°.



I wasn't able to test with the headers I wanted to use which I know for 100% fact cost at least 20+ lb.ft <4000 rpm. The plenum divider was left intact as well, which left another ~20 HP upstairs on the table, but I didn't want to sacrifice the low end torque to get it. We also could've cooled the engine down to ~130° and found another ~15 HP, but again, hero #'s weren't the objective and I wasn't going to go pounding on the #'s matching engine to a $200K+ car just for bragging rights.


I want to thank Rick again for the opportunity to play such a large part in this build. I'm honored, and I'm grateful.

[John]

….

…. This thread is so great

…. Seeing all the details that go into a restoration like this is really fantastic.

… This is what makes this site so great

,,,

[SS427]

Another oddball. Our 69 had what appears to be a 68 Malibu dash plaque on it and can be seen in the original photos. The photo is what I took off a 69 parts car (upper) and what was on the Yenko (lower) which I believe to be a 68. Ours is a March 69 car so not early by any stretch. Has anyone ever seen this in their COPO as well? This car what totally unmolested as far as interior and chassis goes so in no way do I think someone changed it out in the first year of its life.

[Ryan1969Chevelle]

Originally Posted by SS427

Another oddball. Our 69 had what appears to be a 68 Malibu dash plaque on it and can be seen in the original photos. The next photo is what I took off a 69 parts car (upper) and what was on the Yenko (lower) which I believe to be a 68. Ours is a March 69 car so not early by any stretch. Has anyone ever seen this in their COPO as well? This car what totally unmolested as far as interior and chassis goes so in no way do I think someone changed it out in the first year of its life.

Dan Vasic has a black 1969 shell restored and by memory it had the 68 dash trim piece.

Maybe 5 years ago.... let’s test my memory of tiny useless details :-)

Ryan W31

[camarojoe]

There is a white 69 Yenko Chevelle I’ve seen that also has the 68 Malibu dash emblem. Definitely were a few 69’s they came this way for whatever reason.

[21superboat]

If i had to choose based on appearance and correctness a 69 malibu dash plate would be the way to go. Who knows how a 68 plate wound up in there but i wouldnt put it back unless there are other documented 69 yenkos confirmed being delivered this way

[mockingbird812]

Originally Posted by SS427

I recently came across an oddball situation here and am looking for input. Without even a 1% question our car had 100% of its original brakes still intact. During the restoration of the rear axle assembly I found that it had 15/16" rear wheel cylinders and NOT 7/8" like every other 69/70 Chevelle I have come across. Also, the rear hose was 3/16" and NOT 1/8". Chris White actually pointed that out to me while I was trying to buy an NOS hose from 69camarors427 here which is pretty much an exact match to our original so needless to say I bought it and it is now on the car. Has anyone else encountered the bigger wheel cylinder and brake hose on their Chevelle (likely a COPO thing)?

Rick I know this Restoration is keeping you very busy but you asked about wheel cylinders a while back and I responded that the correct wheel cylinder for 69 Chevelle SS is 15/16”. I believe 7/8” is correct for a 70 Chevelle SS. I just restored my original wheel cylinders a few months back and confirmed from my photos that they are in fact 15/16. Good luck

[SS427]

Originally Posted by 21superboat

If i had to choose based on appearance and correctness a 69 malibu dash plate would be the way to go. Who knows how a 68 plate wound up in there but i wouldnt put it back unless there are other documented 69 yenkos confirmed being delivered this way

Thank you for your input but that is not how I operate. One of the things I have prided myself on over all the years is restoring these cars how they were found and built (assuming they were original) and not how the majority of them were built. Case in point is Dana's 68 Yenko with no SS emblems on the fenders. One of a very few that came that way and was restored accordingly as this is part of the Yenko history and I have no intention of changing that history.

Jim S's 69 Forest Green Yenko had no 427 emblems anywhere, no hood stripes and the stripes did not say Yenko SC on the body stripes. I wanted to restore the car that way but he won out. Again, changing history is not my intent so regardless if this is not the correct plaque, that is what came on the car and what will be going back on. I have heard from a couple people already that state they have seen 69's with this plaque.

[SS427]

Originally Posted by mockingbird812

Rick I know this Restoration is keeping you very busy but you asked about wheel cylinders a while back and I responded that the correct wheel cylinder for 69 Chevelle SS is 15/16”. I believe 7/8” is correct for a 70 Chevelle SS. I just restored my original wheel cylinders a few months back and confirmed from my photos that they are in fact 15/16. Good luck

Yes you did and thank you again for that. At the same time almost every other person I have checked with said their car had the 7/8" so I was confused and thought I would put it out in public to see what everyone else had. Ditto on the rear brake hose. Seems to me I asked Dan Vasic this question as well based on how many he has had apart. I have been busy so my apologies for not mentioning yours and my conversation. I need to start writing things down! LOL