Next up was something that came up over the last few weeks and during the drive down to my brothers to do the gears. I had a slight chug at cruising speed and at idle. I couldn't tune it out. I had successfully fixed some minor vacuum leaks last year and had it running pretty smoothly. I was able to narrow this new vacuum leak to the throttle shaft on the secondaries. Sprayed a little carb cleaner at the shaft and she idled up and smooth. I looked into having new bushings put in, and I'm sure that would have worked but opted for a brand new carb instead. After doing some reading I decided on a new Edelbrock Thunder Series AVS 650. Larry from the site here had said the AVS and not the AFB Performer was the better option if you weren't going to convert to a quadrajet. I don't race at all so AVS it was. It's based off the Carter so a lot less to mess with. With just basic vac readings I adjusted the idle mixture and got it pretty smooth after it warmed up. It was set pretty darn close out of the box, fired right up, choke worked great. A short test drive showed excellent throttle response, smooth idle, and no surging or chug! Once I set the trans cable correctly I could tell it's going to be a much better performing carb than what I had on there, and matched up with my new rear gear ratio I'm really starting to feel the true potential of the engine! The 3rd and 4th gear shifts are much firmer so the geometry of the adapter is just that little bit closer than what I was able to make by hand. Front tires are getting rebalanced by my son at school today. I'm hoping for a super smooth and quick car on my second test drive tonight.
I had to make a tv cable bracket before for the 2004r transmission swap, and I had to modify it again to clean up the installation a bit and provide some more adjustment due to the different placement of the cable mount/adapter. I made sure to measure my cable distance to set it again after the new carb was on. Very important step, it only took a couple minutes to get it back to where I had it set before. It bolts on the rear carb bolts, one hole is open for adjusting the initial distance, very simple. Once I got it on and measured up I did add additional surface area for good bolt contact to the carb base.
The installation of the carb was very straightforward. I have a 3/4" spacer in there to make the necessary clearance for the tv cable mount. Without it, there would be contact with the intake. I purchased a fuel line adapter that brought the line back up to the front like the old Carter carb. That was a good decision, I have just a 2" piece of rubber connecting the carb and the steel line from the fuel pump. Also shown here is the tv cable adapter. It's nice to have that on there as before I had to make my own and figure out all the geometry myself.
Here's my goofball son giving me a hand. A garage helper pic, and his prom pic showing he's a master of change! I bet there's a flannel shirt under that tux.
Well, getting the front tires balance didn't have too much of an effect on my remaining vibration issue. So I delved into the driveshaft u joint angles and did some measurements with the Tremec angle finder app on my phone. That worked slick and verified that my yokes were no longer parallel after the transmission swap. What gave me the biggest clue where to look was the vibration I'd get when letting off the gas down a hill. The transmission angle was about zero and the pinion yoke was at 5 or so. So I shimmed the trans up a few degrees and that made a nice difference. I am almost vibration free! A few more test drives and I can verify that I'm good to go. Update: I am pretty pleased with eliminating most of the vibrations, seems getting the trans tailshaft up higher helped a lot. I can't go any further however as I'd hit the tunnel. I am not sure why the differential is angled down so far and to do any more adjustments will require adjustable upper control arms now, that will be next year if I mess with it any more.
That 67 looks great! I see you put rear springs in it, what did you end up going with (mfg/part #)? Mine is in dire need of some rear help, it sags too much. Also, I take it those are 15x7 wheels? What size tire did you end up with front and rear? BTW, thanks for replying to my thread with your timing info! -Rick
That 67 looks great! I see you put rear springs in it, what did you end up going with (mfg/part #)? Mine is in dire need of some rear help, it sags too much. Also, I take it those are 15x7 wheels? What size tire did you end up with front and rear? BTW, thanks for replying to my thread with your timing info! -Rick Thanks! It's been a fun project and fun for the whole family to enjoy. The rear springs I used were the stock ones from Autozone I believe. That was three years ago so I don't have the part number, moogs I think. I do remember looking at quite a few on Rock Auto and seeing if I wanted to use something taller. I wish I would have! I'll see if I have something bookmarked on my computer at home and let you know. I wanted a slightly raked stance and new springs didn't really achieve that, so I still ended up adding air into the air shocks in the rear to get what I wanted. Makes the ride a little stiffer, but if I have five people in there I stay straight! I also added a rear sway bar a few years back also. The tires and rims are 14x6's, they came with the car and I found the set of tires for 200 bucks. I really want the 15x7 and new tires at some point after I wear these out. Fronts are 215/70/14, and the rear are 225/70/14 if I remember right, I don't think they are 75's. Car is in storage so once I bust it out and can be a little more specific on timing and maybe pull a part number off the springs - although I think you would also like something stiffer like a Riviera spring or just a bit taller -1"
Car looks great. I have a 67 gs340 car that some one shaped a 300 in long ago before I bought it. I had a 430 for it but decided to track down a 340 for it. My 300 runs great. What kind of difference did the swap to the 340 provide. I picked up a 340-4 for it but have yet to swap it. I also did yet he 2004r swap and was extremely pleased with it. Thanks again
Thanks!!! You will definitely notice the extra horsepower with the extra cubes and going to a 4bbl carb. That's the main reason I went to the 340, I wanted the engine specs to match up to the rumble it makes. It was also a direct swap and a lot of parts are exactly the same. The mileage decrease is noticeable so be prepared for that. Totally worth it though! I'd say the tranny swap made the biggest seat of the pants difference. I don't know that my super turbine was fully functioning correctly as first gear burned out a month after I got it back on the road. Now that I have some better gears in it, it's very well mannered and easy to drive anywhere. Share a link to your swap when you get to it!
Just a little update here. Did some more fine tuning and did a rear gear oil change. I'm really loving the new rear gear and posi swap! I have been working on tuning the carb a little better, relocated the pcv valve hose to the front of the car rather than the rear, and redid the idle screw setting, was able to go much leaner, reset the choke a bit too. Much smoother idling now and got rid of the fuel smell as well. Changing the grommet in the brake booster eliminated the last vacuum leak that popped up as well. Running smooth! I changed rear gear oil as well, after setting up the gears I did end up with a slight whine on deceleration only from 65 to 35 mph. A local shop recommended I upgrade the oil I'm using as all my specs were darn near dead nuts and a lot of todays gears have some degree of noise. I had used 80w90 synthetic with the additive. It's evidently on the thin side and after draining it our and measureing the amount I was a little low for some reason, 36 oz came out and I was able to put in 60 oz of the new stuff. I went with Castrol GL-5 traditional 85w140 with the true GM brand limited slip additive, 2 bottles was recommended. That eliminated all the noise in the rear, seams to have fixed it. Here are the patterns from the gears after about 2500 miles. This is my second fluid change, first after 500 miles. Pattern isn't perfect, but it's quiet so I'm going to run it unless somebody tells me they can get it closer!
Latest update is the new tires and rims. I bought some 15x7 rims from a member on the board and that enable me to put 255/60/15 Cooper Cobra's on the back and 245/60/15's on the front. No rubbing so far but I will verify that this week. They look great and finally give the tires some better proportion. The handling is much better as well, which is a nice surprise. Update 5/4/18. I put 1.5" aluminum spacers under the rear springs and let all of the air out the shocks. Now it sits properly without so much air pressure in them. From floor to wheel trim it is sitting at 26.25" and I have plenty of clearance for the 255's. If I ever have 5 or 6 people in there I will have to watch it, but looks great. I was able to do a little trimming on the inside of the lip to maximize clearance as well, maybe and 1/8" on one side and 1/16" on the other. Should be golden now!
Great looking build @67skylark27 I appreciate reading about your build as I am looking to mirror your upgrades. Thanks again for sharing.
You bet, I put all this in here so others can have a guide with what works and what doesn't. It's been my learning car so when I do the next one, I'll do things even better. Good luck on your car and feel free to message me anytime.
Here's a new photo after a full wash and wax and with the new tires and rims. She ran excellent this weekend and took it to the NWTC Car Show again. Picture is taken at the Chase Stone Barn Park, one of the oldest and largest stone barns remaining in the country.
