1968 Vert - generic small block. Quadrajet
After Action Report (AAR)

Removed pre-existing 1966 cast iron manifold, replaced with Edelbrock Performer 2101.
No major surprises. Three issues:
(1) The 2101 has provisions to install the 1971 and up divorced choke thermostat using a special Edelbrock choke rod. 60's chokes need not apply. Ordered the Edelbrock rod and the GM choke. Have rod, no choke till mid-week. Car still starts - just harder.
(2) Overall height was slightly higher. My (14") aftermarket air cleaner base only has about a 3/4" drop at most. For now I replaced the 4" filter with the 3.5 inch Purolator A601012. More than enough air for a tired old small block.
(3) The right front heater hose outlet faces straight up, the 66 manifold exited more to the side. Ordered a right angle fitting to fix that.

As a bonus I moved all the plug wires by one post and got the dizzy in straight this time. The tach cable is not quite as "happy" as it was with the dizzy in wrongly, but overall is more "correct" now.

I won't get my vacuum gauge back from forgetting it on a customer boat until the weekend. (we talked already). So I channeled my inner Bubba and set the 2 idle screws on the Q-jet by ear. In slowly till it falters than out 1.25 turns - close enough till Saturday - exhaust smells normal.

Test drive. Allowed the car to fully warm and took it out for a mild romp.
Top end is hard to gauge because valve float in the tired old beast limits it to about 5k, anyway. But what I felt was notable improved torque in the 2000 to 4500 range. With the 3.70 rear end, it was always a bit of a torque monster, but this was more so. Had to re-adjust pedal pressure to avoid breaking it loose (or staying loose) when zerging it through corners. Overall pleased!
-W

Afterthought: If /when I actually do a new 427SBC build - this manifold and carb stays. I don't want to be forced into the L-88 hood. The 327 and 427 hoods are fine (not sure if the 427 hood has more clearance in the carb area?) but I just don't like the "character change" of the external lines of the car with the L88 hood. And I suspect I would't much like the "new view" from behind the wheel after 40 years with current view.
Pic is of completed project.

 

are you aware that GM issued an update on the plug wiring so that having the vacuum unit pointing straight to the passengers side is considered correct thus not binding the cable? Read page 4 of the document.

http://www.corvette-restoration.com/...stallation.pdf

 

That so funny it's almost pathetic.
That's the way I had wired it instinctively before the manifold swap. I changed it this time because of all the comments that it was on wrong because the cap wasn't straight. LOL! It needs a new tach cable (inner) anyway the needle bounces at low RPM's - it sat too many years tweaked in one position. I'll likely leave it straight *for now* and see how long the new cable lasts. If / when I build up a 427 SBC - it can be re-addressed then. Bigger fish to fry.
-W
PS: See this youtube link for a super easy "first drop" install. Slicker than snot. (all the meat in in the first 3 minutes)

 

Glad to see it all worked out well for you!

One thing though......If you ever do the 427sbc, (and I suspect you would want more horsepower), I would definitely not keep that manifold/carb combo. You would be leaving about 50hp on the table.

 

Thanks! - Yes; That's going to be another whole thread......
I have some strange paramaters (like the no L-88 hood) that might limit the 427 build - might also save me money too! LOL

 

I like the stock SBC hood look. Your 68 looks great. My 69 434 SBC with a 2101 on it lites up 285 40/18x10s with 3.08s and auto. T

 

Yes. I'd be willing to leave a few high RPM HP on the table to keep it looking "correct".
Ditto exhaust. Best flowing "ram's horn" type headers is as radical as I'd go.
-W