I have been reading eveyones reviews of the Proform main body and I would like to upgrade also. The only thing that concerns me is the fact that I have one of those Nitrous switches that mounts on the side of the main carb body where the manual choke used to be.

My question is, does the Proform main body have provisions for my nitrous switch screws where the manual choke goes on the side of the body? It looks like it does not but please tell me I am wrong. Thanks

 

I finally got out and looked at mine tonight. The DP version, at least, has three untapped bosses, but they don't form a triangle, and aren't quite the same as the ones on the 650 DP Holley main body it replaced.

 

Again, thanks.

 

I'd take pictures for you, but the digital camera was left in the back seat of my mother's car back in October, and I won't be able to retrieve it until Christmas...

 

Not to steal a post but Five&kid- Are these main bodies set up for 4-circuit idle or 2? Can you even use a 2 circuit idle system on them or do you have to convert to a different rear metering block with idle screws and a power valve?(I'm talking the DP version-I'm replacing a 2-circuit idle 650)

 

I dont think the Proform main body is worth the cash... actually I dont think any Proform product is worth the cash.

 

The Proform is set up for two-corner idle mixture adjustment. There isn't any provision for ported vacuum, either.

Personally, I think it's pretty slick. But, I didn't have the DP in long enough to gather much data before converting and doing other things.

 

It does both 2 corner and 4 corner. You just have to change out the secondary idle air bleeds from 73 to 36 if you use only 2 corner idle. THey are included with the kit. Very well made body. Turned my 650 DP carb into a 750 HP style carb.

 

I'm bringing this back from the dead because I've been having idle issues this spring.

I haven't any idle problems since installing the mainbody, until I fired it up with the new cam back in March. I couldn't get it to idle, even on gasoline, and kind of nursed it along as I switched over to E85 (another story). One TGO member suggested I open up the secondary blades, which helped a little but it still acts like it's got a big vacuum leak (can't find a vacuum leak, though).

Thinking something happened to the circuits over the winter, I took the carb apart and put a kit in it. It didn't look at all bad, so instead of soaking everything in dip-type carb cleaner I just sprayed canned carb cleaner through everything. Didn't help a bit. I took it apart again and soaked it in the dip cleaner, chased all of the passages (and verified the mainbody has 4 corner idle circuits built into it). After all of that, it will idle a lot longer than it used to, but still at too high of RPMs and it will eventually die if I don't stay with it.

I was thinking I'm probably going to have to go to 4-corner idle when I searched and found this thread. I still have the large bleeds in the secondary idle circuits, I don't remember any 36 bleeds coming with the mainbody or anything said about it in the instructions. I'll check later tonight, but maybe this is what's causing all of my problems.

The other choice is to go ahead and do the 4-corner idle.

 

I verified no extra 36 air bleeds came with the mainbody. Looking at the original 650 mainbody, it's clear the primary idles are much bigger than the secondary idle bleeds.

So, I'll be picking up some 36's after work tonight.