First quadrajet rebuild

[Kevinb1]

The closest I have ever come to rebuilding a carb was watching my dad doing it sitting at a picnic table when I was young. I've purchased cliffs rebuild book and just recently started reading it, and now I'm not certain how far to take the rebuild. I don't want to do unnecessary work. I'd appreciate it if someone could give me a list of all the items I need to do and parts I need to buy from Cliff that work with my motor. The motor modifications I have a made are very limited but are as follows;
68 327 bored .30 over
Mutha-thumpr cam, 107 lobe separation: 489/235 intake lift/duration, 476/249 exhaust lift/duration
Cam has been degreed for low end power bc I don't want to turn the engine at high RPMs
Double hump 1.94/1.5 heads with Z28 springs
Stock intake and exhaust
Stock point distributor, not certain if I should change the spark curve or not
4 speed transmission
3:08 rearend.
The car will not be a street racer or drag car, but I would still like to have the carb tuned to my set up.
I know that I will need to replace the bushings but don't know what other items I should change out or improve on for my engine.
Quadrajet 7028212 DH
Do I change the accelerator pump beyond stock?
Which primary metering rods do I need?
What secondary rods should I use?
These are just a few questions I have so any help would be appreciated.

[carmantx]

Call Cliff, he will walk you through what you need and supply them for you.

Yes, you will need a new accelerator pump, and primary rods/jets.

You may need some idle circuit modifications with that cam, but Cliff will help with that also.

[Kevinb1]

Thank you for the response.
I called the number and left a message. Hopefully I will get a response soon. I want the entire running gear ready when I'm done with the engine soon.

[429bbf]

ouch,if that cam is anything like my buddy put in .i can't build a carb to make it run good , maybe you can but i had living heck. my friend bought this thumper cam . maybe we're  not talking the same cam , anyway the thing sounded COOL but that was the extent of it , his first problem was not enough compression , second way to close of lobe centers , no matter what i tried the thing ran like crap,no power , a poor running 235 chevy six would have beat it . he finally changed out the cam and raised the compression and we got it to run good.maybe if he would have had more compression it would have worked won't ever know because he did both at the same time.purchase a sr kit from cliff , if the throttle shafts are loose put bushings in, if you don't have the tools or don't want to attempt it send it to cliff he does it for a reasonable fee. fwiw

[77cruiser]

Sorry to say NO WAY will that cam have low end power in a low compression 327. Cut about 20 degrees off & it will run pretty good.

[von]

Yes that cam has to go. With that much duration on tight lobe centers, a 3.08 rear gear, and manual trans your car will be the biggest dog you can imagine. With your heads, intake, gears, etc., you need a cam with duration at .050 lift in the zzzzz or low 20's at most with LSA at least 112.

[Cliff Ruggles]

I discussed cam choice with the owner a few days ago.

By far and above the biggest complaints I'm getting to the shop are from folks who have installed really tight LSA cams in their new engine builds, and specifically the Thumper and Mutha-Thumper series cams.

They hate the "stinky" exhaust, and the engines refuse to idle below 1000-1200rpms without a TON of timing and idle fuel, and still very "lazy" off idle and low rpm's.

One customer with a 454 with 10 to 1  compression was trying to use one about the size of the one mentioned here in a stick shift car and had to "two-foot" the brake/clutch and slip it considerably if he stopped on a slight grade and had to start out again.

He yanked the cam and went to a Speed Pro grind on a 115LSA and cured all the issues.......Cliff

[von]

FWIW I typed "zzzzz" for duration a .050 lift but for some reason it printed "zzzz".

[von]

It did it again. For some reason what I type doesn't get printed.