Carb Help

[bbaspense]

I'm running a Holley model 4160 750 CFM Vaccum Secondary Carb (3310-4).

I have a few questions......

Has anyone used the Proform Main Body that you can buy for this carb.
They say it's new design is worth 25-50 horspower.. they say that you can reuse all of your existing setup but it has a milled top, screw in air bleeds....only $100 from Mancini Racing... sounds like a good deal for 25 hp...... is it worth it?

Any luck with this kit?

Second:
My carb came with a metering plate... can I change it to a metering block so I can easily change the secondary jets..?? What block can I use or am I stuck with the plate...??

Third:
Is it worth upgrading to the 50 cc accel pump at my performance level?... do I need a bigger shooter if I do?



My combo:

400, stock piston, 484/292 cam, M-1 intake, windage tray, 3000 converter, 3.91 gear, 26 inch tire, shift at 6000 go through the traps at 5800..

12.80@ 107 at 3800 lbs.... 1.85 60 ft..

[Doug Wilson]

I read that the Pro-Form main body is really worth the money.

You can change to a metering block - check Summit, P.A.W. or Jegs.

I wouldn't change the accelerator pump unless you are bogging.

[bbaspense]

The carb does have a small off line stumble but it seems to have cleared up a bit.....

My accel pump shot is all done by just over 1/4 throttle.... I'm thinking that maybe I need a longer shot... maybe try a few different accel pump cam profiles....

The carb also doesn't run a power valve... I kept popping them so I took them out and upped the primary jets 5 sizes.....

[Doug Wilson]

I'd get the different cams before I increased the voulume of the pump. The lack of a power valve might also be causing your stumble. Did you try several different ones before you tossed them.

Also, if you are blowing power valves all the time, it indicates something else is wrong.

Is this a race car only?

[Doug Wilson]

By the way, you have a helluva strong combo there. Any pix of the car and engine??

[bbaspense]

I drove it for a while on the street with no power valve with no problem.... a little rich though....

No the car is just a race car....

I blew 5 in a few months and got sick of the hassle so I tossed it.... no problems anymore..

When I bring the car up on the converter , 2400 rpm, and launch... there is no stumble...

It's only when I leave from idle...

[Doug Wilson]

Then don't leave from idle.

HaHa!!

[bbaspense]

I'm very fortunate the combo works as well as it does...

The short block was honed and reringed... I couldn't afford to bore and put new pistons in it so I just put it back together..

The crank was polished and chamfered.....

The cam is in straight up and I lost the cam carb so it's not likely to get adjusted....

The heads are pocket ported 452's.....

The engine was put together in '98 and finally I'm getting it sorted out... The engine wouldn't get past 13.39 @ 103 using the stock intake so I spent a few bucks and put on an M-1 intake... that sropped me to 13.20.... that was shifting at 5500...

My buddy said to try 6000 as my shift point so I did and the car went 12.80's..... wow........

I'll be getting some pics soon from the track...

It's just a 77 Aspen SE with full interior and column shift...