Make My Own Metering Plate?

[PurpleBeeper]

I've got a '70 4spd six pack setup with front carb #4382. It's been running "pig rich" and the carbs have been modified, so I'm trying to put them back to stock and work from there.

This particular carb (#4382) calls for a 34R-6153-34 metering plate. I can't seem to find this metering plate (at least Chicago Carburetor & Six Pack Performance don't have any). Right now, I have a 34R-6153-35 metering plate in BOTH my front & rear carb since that's all I can find. Art at Six Pack Perf. was kind enough to tell me the orifice holes on the -34 plate are .089" pass. & 0.093" driver's side. I'm trying to avoid the expense of the ProMax metering plates with regular Holley jets in them.

Does anyone know how I can make my own -34 plate? Is there a similar secondary metering plate out there (same configuration with smaller holes) that I can just drill out to .089"/.093"? What about the -35 metering plates?

Thanks for Your Help!

 

[lewtot184]

what size are the main orifices in the plates you have now?

 

[PurpleBeeper]

what size are the main orifices in the plates you have now?

Hey Lewtot184, I'm not exactly sure. Right now I'm running the 34R-6153-35 plates in both the front and the rear carbs. My original plates I drilled out myself back in '85 or so (stupid me).

Since I've been chasing this rich issue, I've been trying to "un-modify" the carbs to get a good starting point. I "thought" that front/rear on a '70 4spd were both -35's, but now I see on the Chicago Carburetor site that the #4382 (front) should use a -34 metering plate & the #4383 (rear) uses the -35 metering plate I already have in there. It might not amount to a hill of beans, but I'm trying to get everything back 100% stock as a starting point.

To answer your question...."whatever size the -35 plates come stock" since I have un-drilled -35's in both my front/rear carbs.

 

[lewtot184]

looking at a plate i have it measures .089/.093. revised bulletin #2 states: .089/.089 front and .093/.093 rear with heat blocked and edelbrock intake. i don't think there's much to be had by going larger than .093 on all corners in a mufflered street car. i doubt the plates are your issue.

 

[PurpleBeeper]

looking at a plate i have it measures .089/.093. revised bulletin #2 states: .089/.089 front and .093/.093 rear with heat blocked and edelbrock intake. i don't think there's much to be had by going larger than .093 on all corners in a mufflered street car. i doubt the plates are your issue.

Thanks lewtot184, but I'm a little confused. Are you saying you have a 34R-6153-34 or a 34-6153-35 plate that measures .089" pass / .093" driver?

My issue is that I think the stock plates for my carbs are 34R-6153-34 (front/4382) and 34R-6153-35 for the rear/4383 carb. I have two stock, undrilled 34R-6153-35 plates, so I've got the stock rear/4383 plate, though I have no idea what the metering hole sizes are.

I'm wondering if I can make my own front plate that's .089"/.093"? I'm shooting for absolutely bone-stock, non-oversized metering holes front & back.

 

[PurpleBeeper]

Maybe I should ask this question..... What are the fuel orifices (driver/passenger) on a -34 metering plate? On a -35 metering plate?

Also, are there any metering plates the same configuration as a -34 plate with smaller holes that I could drill out to make my own -34 plate? I've seen a partial list of metering plate hole sizes but it didn't list the -34 plate + I don't know if I can just use a metering plate out of the back of a 3310-3 Holley 4-barrel (or other carb) and modify it or not.

 

[lewtot184]

i've got 34 and 35 plates. the numbers i gave you are what my plates measure. actually the .089/.093 plates were for cast iron intakes. to my knowledge all alum intake carbs had .089/.089 up front and .093/.093 rear. a lot may depend on your engine modifications like cam, headers, heads, etc.

 

[BadBee]

Not to hi jack the subject LEW but where is the best buy on repop six pack carbs?
the places mentioned above?? Any place else?
thanks,
Mitch

 

[lewtot184]

Not to hi jack the subject LEW but where is the best buy on repop six pack carbs?
the places mentioned above?? Any place else?
thanks,
Mitch

i haven't bought new carbs since the mid '90's. i'd just look for the best price with a vendor you trust. i don't think there are any deals, but could be wrong. i do so much stuff myself to where i'm just not vendor savvy anymore.

 

[69 GTX]

For me Jegs was the best price.

Lew couldn't he just plug and redrill the orifices ?

 

[kiwigtx]

I bought these QF metering plates a while ago for a future rebuild....

http://www.summitracing.com/int/parts/qft-34-3/overview/

Would these be useful to Purplebeeper ?? :hello2:

 

[lewtot184]

For me Jegs was the best price.

Lew couldn't he just plug and redrill the orifices ?

back in the day, and i mean way back, i used lead plugs and drilled and tap for jets. in my opinion, the real issue is that there are no major gains from rejetting with a stock or moderately modified engine.

here's the 1971 factory race jetting (probably s/s, big cam, headers, etc.): front-.093/.089, .070IFR

center- 65 jets, .052PVCR

rear- .093/.099, .070IFR

- - - Updated - - -

I bought these QF metering plates a while ago for a future rebuild....

http://www.summitracing.com/int/parts/qft-34-3/overview/

Would these be useful to Purplebeeper ?? :hello2:

i've got a set of those. they don't fit very good, but might work better if the quick fuel float is used vs the holley float.

 

[PurpleBeeper]

I bought these QF metering plates a while ago for a future rebuild....

http://www.summitracing.com/int/parts/qft-34-3/overview/

Would these be useful to Purplebeeper ?? :hello2:

Thanks kiwigtx... those plates are a lot cheaper than Promax ones, but do they come with floats? The Summit link mentions side-hung floats & notched floats, but they're not shown in the picture. I know I should be using adjustable front/rear metering plates, but cash is really tight for me right now. Summer is just about here and I can't justify much money spent on the ole' runner to my wife.... but I want to drive it!

I worked on this problem all last summer.... I want to drive the car "on the cheap" for now. I'm very tempted to just leave the un-drilled 35 plates in both the front & rear carbs, but I'm STILL not sure what effect that will have. All I know is the book says -34 plates on the front a 4382 front '70 carb & I've got a -35 in there and it won't idle right & is running very, very rich.

I've got a cast-iron intake, Comp Cams 21-224-4 278/286-488/491 cam (downsized from old 292/509 purple cam), about 10:1, cast-iron heads if that helps.

 

[69 GTX]

I installed them in my carbs with out issue (the QF plates) just recently. Also make sure your timing I set correctly. Something like 16-20. Use a vacuum gage to set timing and idle till highest reading is obtained then start on the carbs.

 

[kiwigtx]

Thanks kiwigtx... those plates are a lot cheaper than Promax ones, but do they come with floats? The Summit link mentions side-hung floats & notched floats, but they're not shown in the picture. ...............

No...you get the plates only for that price. Floats are extra - and I did not go ahead with the mods just yet. I am running a period Holley carb for now, and it works great.

 

[PurpleBeeper]

No...you get the plates only for that price. Floats are extra - and I did not go ahead with the mods just yet. I am running a period Holley carb for now, and it works great.

I was unable to find a -34 plate, so I kind of changed boats mid-stream & bought two 34-3 Quick Fuel metering plates & two sets of #80 and #83 jets (will start with 80's since I've been running rich). I also got one of those mechanical advance limiter plates for the distributor and an un-drilled center carb metering body (my current one has power valve holes drilled). I'm going to give this six pack one more good chance. I'm going to re-set the valve lash (adj rockers), check the plugs, set the timing until as dead-on as possible, rebuild the carbs again using #80 jets in QF outboards, 31 squirter, white accel pump cam in #1 hole, 30cc accel pump, switch from short yellow outboard springs to long yellow, dial in the fuel mixtures on all three carbs & re-set timing if necessary. I may be dreaming, but I want to hook up the vacuum advance if I can, but I'm not holding my breath. I should know in 2-3 weeks.

 

[BadBee]

Good Luck Purple!! I must say you've BEEN AT IT HARD BRO!!

 

[PurpleBeeper]

I finally found most of my metering plate info. The -34 front plates (one's I can't find) have main metering holes of .089"/.089" and the -35 plates are .086" pass//093" driver, so I can't quite make a -34 out of a -35 since driver's side main fuel hole is already bigger. What other secondary metering plates would physically fit? Is there another plate with .086"/.086" (or something like that) which could be drilled out to make a -34 plate?

I'm also realizing that there are IDLE fuel holes in the metering plates in addition to MAIN fuel holes. My issues seem to be related primarily to idle fuel mixture & I'm currently trying to "jet down" to make sure I'm not making my idle mixture too rich because I'm way over-jetted. The -35 plates I have now in both front/back aren't drilled out at all (idle or main)....hmmm... this ain't getting any easier.

 

[Photon440]

If the hole is too big, solder it up. Then drill it to the size you want.

 

[62MAX]

I've got a '70 4spd six pack setup with front carb #4382. It's been running "pig rich" and the carbs have been modified, so I'm trying to put them back to stock and work from there.

This particular carb (#4382) calls for a 34R-6153-34 metering plate. I can't seem to find this metering plate (at least Chicago Carburetor & Six Pack Performance don't have any). Right now, I have a 34R-6153-35 metering plate in BOTH my front & rear carb since that's all I can find. Art at Six Pack Perf. was kind enough to tell me the orifice holes on the -34 plate are .089" pass. & 0.093" driver's side. I'm trying to avoid the expense of the ProMax metering plates with regular Holley jets in them.

Does anyone know how I can make my own -34 plate? Is there a similar secondary metering plate out there (same configuration with smaller holes) that I can just drill out to .089"/.093"? What about the -35 metering plates?

Thanks for Your Help!

Q/F has a cast plate,1/2 the price of the billet ( picture attached) and there are no fitment issues or float interference but you have to get it directly from Q/F.As for Promax,never could figure out why they are priced as high as they are. I have quite a few plates if you choose to go with original.You say you are running rich,at speed or at idle and also what jets in center carb?