I figure I might try to document the conversion of the 65 Laurentian, from power glide to a 4 speed Muncie M20. I'll ad that Carl Stevenson has been a invaluable resource on this conversion, and has helped me out immensely. thanks Carl! And be sure to check out Dave's conversion post sticky as well.
I'll start with making an inventory of ALL the parts needed, in the attempt to make a reasonably authentic bench seat 4 speed car. Pictures and description, along with questions. If you have anything to add, links, pictures etc, please do!
I'll start inside the car...
Interior;
Shifter handle: 65-66 bench seat; Muncie reverse lockout shifter handle. Correct curve for a 65-66 bench seat car, maybe 67 as well. There are many types out there. Beware, people try to misrepresent this part all the time. I've found an original after buying what was a maybe Chevelle handle. The attachment describes different shifters console/bench. Expect to pay $150 or so for a decent shifter. All types of balls are available for it.
Boot; The correct 65 boot is not available aftermarket. If you find one NOS, expect to pay at least $300 USD for it. I've chosen this one shown, supplied by Hubbard's Impala. I don't know what it would be for, but it will have to do as a reasonable facsimile. $50. The correct boot is shown at bottom with a image of an original 65 setup. Kind of square on the bottom, with a section of rounded pleats on top. I think this was a 1965 only part. So it's super rare. Perhaps somebody has more knowledge about these? Chime in please!
Boot ring: secures the boot. I've bought 2. One I'll use as the opening ring when I attempt to fabricate a shifter hump.$15 ea.
Carpet Ring; Trims the edge of the carpet where the boot comes through. Has a 3/4" slit around the edge. Supplied by Stevenson Inc. Should fit the boot I'm getting. Flexible plastic/rubber. Can be painted to match the interior trimcolour. $50
Steel Ring, Boot and Carpet ring all stacked together. Will work just fine! Turns out the boot sold through Hubbard's as a 65 to 66 bench, is actually a nice SoffSeal part (which is good), listed for a 64. SoffSeal 2109 or Hubbard's 6466SBUM.
Carpet; A high quality floor shift carpet is available from NOS. I'll buy it before I make the hump, just to be sure. As Carl states below, avoid the actual 4 speed carpet for a 65-66, the hump molded in is far too big for those years.
Tunnel shifter hump; The one shown is available, but according to those who have done it, it's a piece of crap. $80!!. Sorry, I'm going to attempt to make my own.
Steering Column; Of course you'll need a column without a shift lever. Here's a 65-66 floor shift column. Good supply, fairly easy to find. Easy to rebuild, all the parts are available. Bolts right in place of the column shift unit. Same wiring.
Clutch and brake pedals; Can be bought aftermarket, never heard any feedback on the non OEM offshore parts, but I suspect they are not a robust as the originals. You can buy the pedals separate or as an entire 4 speed "Clutch" conversion. I bought a pair of good originals with rods and the Z bar. All the pedal bushings, the shaft and the clip are all available new. So you can restore any old set. I think 65-70 is interchangeable across, as in all will likely work, but as witnessed by Dave's great image, they differ in size, shape and the stop position. 65-66, 67-68, 69 along with 70, I assume.
Pedal Pads: Deluxe or standard pads are available reproduction and are cheap. I've chosen the standard pads. The base cars for the most part got this style I think? Did a base power brake car get the pad with "power brakes" on it?
To note, the CPP branded pads received are of the cheap stinky offshore rubber. Even a little slippery! A scuff will probably make them usable.
This will be very helpful to me if I decide to convert my 68 Bel Air to a 4 speed. Fortunately I have everything described except the hump and the Muncie shifter. But I do have a Hurst shifter that fits this application. I will watch this one closely. Thanks for posting it.
Well, a few words.... For a 65-67 bench seat conversion, when you order the carpet, do NOT order a 4 speed carpet. The manufacturers have this totally wrong and refuse to admit it. They mold the 4 speed carpet with the 68-69 hump which is TOTALLY wrong. A regular bench seat column shift carpet is perfect. I'll look for the link where I posted on this way back when I was working on the 4 speed conversion in my black 66 Grande Parisienne that Tom bought.
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
Well, a few words.... For a 65-67 bench seat conversion, when you order the carpet, do NOT order a 4 speed carpet. The manufacturers have this totally wrong and refuse to admit it. They mold the 4 speed carpet with the 68-69 hump which it TOTALLY wrong. A regular bench seat column shift carpet is perfect. I'll look for the link where I posted on this way back when I was working on the 4 speed conversion in my black 66 Grande Parisienne that Tom bought.
This is good to know! Thanks!
__________________
65 Laurentian post, 67 Grande Parisienne 4 door HT.
I have spread the word on this issue as much as I could, including over at Chevytalk where one or two other guys have had the same issue. I don't understand why the manufacturers won't admit there is a problem and the carpet they sell for 65-67 4 speed cars is WAY wrong...
At the end this thread gets totally derailed but lots of info at the start at least---
I used the regular ( non 4 psd ) carpet on my 65 Biscayne post, and it fine over the factory 4spd hump. The 65 has is a very low profile hump not as pronounced as the 68 /69 as shown in pics .
-- Edited by Howmac on Sunday 5th of May 2019 04:59:03 PM
In adding to this dormant post, I did a little work and mockup on the Muncie shifter. Cleaned it all up, and began to assemble it on the bench in an effort to see how it actually works.
Put the case together with no guts, but with the sidecover combs, spring and shifter forks in place. Figured out the rod configuration from a shop manual illustration. Cleaned up the rod threads.
Shifter levers were put in the neutral position, along with the case levers. Interestingly, this shifter has no neutral square "slot" so to speak of, just basically a half moon shaped slot. No place to fit a neutral gauge feeler. So it's basically find the position by eye while adjusting the rods. I'd made the red lines with the levers out of the case while observing the square slot being lined up all the way across. Maybe this half moon is a clue to as what model this unit came from. The 65 manual shows a slot. So any ideas?
I'd bought two different "shims" as suggested by Carl Stevenson, to maybe take up some of the slack you might find in an old worn shifter. I've since found out that the "Shim" is actually more than that, it really is a protection gate inside the shifter to prevent a false reverse moving 1st to second. While the shifter lever has a lockout pin, still, it makes sense to have this extra square edged gate. It actually sits fixed in the body and divides the reverse/1st and 2nd levers. One shim was .073 (stock thickness), and the other is .099. Looks like the .099 will fit. Will need a trim (on the score lines on the black), as the replacements are actually Corvette parts. Identical everywhere but the ends. Another great solution from Carl, I don't think a identical replacement is available.
Picture shows the "shim" in place, red arrow, yellow is the half moon slot for neutral. .099 shim shown how it would sit inside the cluster. The square slot is the gate. The lines on the black are the trim lines.
Mocked up, clamped to the bench.
So even with the stock shim, as mocked up, it rows and clicks through and across all the gears with ease. Mind you, it's a mockup without actual gears, but it still feels very good. Sweet! I can only imagine how nice it will be sitting on a bench while rowing! I think fitting the .099 shim will even make it sharper. Finding a nice even neutral across all the levers at the same time to start is the trick. I'll do one final neutral gate test before it goes in the car
I always love learning about something I knew zero about! Next, I'll put the M20 together. Cheers.
Mark, a 5/16" bolt will get those gates lined up real nice once you have the rods installed. I take no credit for helping you, I'm just passing along info that others have shared with me in the past.
For anyone interested, more detail on the conversion. Here's a very good, not often seen image of an original factory 65 4 speed impala firewall. A small but mostly overlooked detail.
Shows the speedo cable, hangers and grommet position. Looks to be just a regular grommet for the most part. Not shown is the Fisher Body cable clip or tab under the passenger floorboard edge.
Notice the assembly manual calls for a 1" hole, and the automatic cable hole is to be plugged. Also the fW is described to be dimpled for the hanger bolts.
Is the grommet just a "regular grommet"? And is that underfloor tab in place on some or all cars?
Used the 65 factory assembly illustration and factory dimples to position the clips and bolts. Used some Inline Tube fuel line clips and self drilling/tapping bolts.
Cut the new offshore repop grommet to get it over the cable, and glued it back together with Ultra Black. Clipped into the new 1" hole nicely.
If you have a good original grommet, the small cable nut can be teased through the grommet with a little effort. The repop was just too thick and hard to do so.
Thanks for the great photo Mark. I have a more distant one of a 67 (same setup) but that's a great shot. Guess what I meant to do but forgot when I had my engine out last winter....
I plan to pull the trans, bellhousing and flywheel this winter so I hope to change it then.
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
I had bought a Z Bar bracket from an Impala parts house. But the biggest issue is where to mount it on the frame? It's one of those things that really cant be measured very accurately.
It's been on my mind for some time now, so I figured that before I put the M20 together, I'd just mock it all up bare and just simply drop it in to simulate the positioning. Cleaned and zinc primed the landing spot for the bracket. Fitted the trans mount with two studs protruding down (where it would be bolted to the Crossmember). Centered it all with the firewall centerline, and raised it up with a strap to the point that the bar pretty much sat horizontal and square to the body. Also, since the crossmember holes are elongated, I just let it all sit about mid point in those holes. Used a small but long Bessy clamp to hold the bracket in place, accessed through the wheelhousing.
I figure one key part of this was to make sure the Zbar lever, clutch pedal side, sat in the right spot for when the rod comes through the wall, and into the little rod mounting block. Although it's probably pretty forgiving, I made sure the rod will center in that firewall hole. You can see this by the line in the image on the right. I think this is your best clue as to if you'd got it right.
Traced the location of the bracket as it sits. I think it's all good.
Now I can work on getting the M20 together. I'll weld the bracket when I detail/repair the engine compartment.
There should be a bit of a dip on the top of the inside edge of the frame rail to accommodate the z-bar. I was fortunate when I did mine as the body was off the chassis, and I had a bare block to bolt the bellhousing & tranny to. Once we put the z-bar in place, the small dip on the top of the frame rail was obvious.
Clint, you can see just a hint of the divot you speak of in the right picture. The bar comes over right on top of it, so I suspect I'm in the right spot.
__________________
65 Laurentian post, 67 Grande Parisienne 4 door HT.
Clint, you can see just a hint of the divot you speak of in the right picture. The bar comes over right on top of it, so I suspect I'm in the right spot.
Yes, from what I recall the bar was pretty much centred over the divot.
If the mockup works out right with the clutch fork rod and the clutch pedal rod at the Z bar I'm sure you'll be fine Mark.
If you can rip apart/rebuild a Turbo 400 when you've never done an automatic before I'm betting on you to nail this simple task with very little effort!
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
2nd, 3rd and fourth (input) gears as the syncro dogs were chipped. They're Italian gears without the tapered "locking" dogs.
1st gear was in decent shape so used that one.
Purchased two matched "zero rock" syncro hubs and sliders from Paul Cangialosi.
New syncro rings.
New 1st gear bushing, the improved version with diagonal oil grooves.
Polished the syncro hubs on all gears. Something apparently you need to do on any new gear to prevent a possible stuck ring. Did 600 then 1200 wet paper with oil, then metal polish on the cones.
Managed to get the thickest (.100) midplate retainer snap ring in place.
Gears spin freely on shaft. No bind.
One issue...messed up on the steel speedo gear, heated it up, slid it on but it landed too far down the shaft. Cut it off. Will buy another as the plastic one with the clip looks pretty tired.
