Those will be fine, I was looking at this this morning and many use Holley 600 vs carbs.

 

Might look into leaning out the idle, two carbs twice the fuel.

 

Might be totally off base but.... decades ago.... with old Edelbrock/Weiand tunnel ram intakes, backed off the adjustment screw to completely close the primaries blades and used the small set screw under the throttle plate base, raising the secondary's lever to set the base idle. Seemed to work better than drilling holes in the butterflies.

Tuned with an abacus though.

 

It depends on if the carbs are 4 corner idle, you would approach that with smaller IFR TSR, If only primary idle, shouldn't be and issue, normal tuning would take car of it.

 

Yes they are 4 corner idle.

 

What transmission are you using ?

 

I have an ancient pair of 650 DP's that were used on a BBC blower application. Not sure what all was done to them but I've never seriously considered using them on any of my SBF stuff thinking they were probably just too big for what I'm doing.

 

What transmission are you using ?

Tkx

 

I can only give you the suggestion of using primary power valves, and use progressive linkage ( opening secondary's at 1/2 throttle)

 

A pair of 650DPs will be great for that engine. If you can find and old guy who used to run Modified Production or a similar class back in the day, get him to help set them up. I had a guy build my 750s who does "tons of carbs for 1600hp no prep cars", but when we bolted them on they were so rich they stunk out F.J.'s dyno room. He pulled the carbs, removed and plugged the power valves, rejetted, and now they work great, but were down 3hp@7500 on my 369" sbf to a pair of Braswell 650s that started and idled more crisply, and seemed to be more strong and responsive across the board. I think 650s would be a great carb for the cid, rpm range and power range you're shooting for.

 

High rise will give you fits on the street, they're designed for 7000rpm and above.
Recommend a low rise for the street or Holley Sniper sheet metal malifold if one is available for your setup.

 

This has not been my experience with this particular intake.

 

This is what I have on these carbs.

 

What about emulsion sizes/locations? Too much high speed air and too late power valve opening IMO

 

WOW alot of carb really for this deal, and pricey as well. Not saying they won't work and should be ok. I have been recommended the 600Vs carbs for a tunnel rammed 468 BBC in the 750Hp range.

Allstate carbs offers a set of modified 600vs for tunnel rams for $850 or $780 for shinny. But run what you have and fine tuning should help get you some good driving characteristics.

 

These carbs were about 700 each.

 

I've had the most success with removing the power valve altogether and jetting to compensate. It just takes another variable out of the equation for a caveman like myself.

 

Is this your intake?: If so, I think that motor of yours is going to make plenty of grunt, and rev pretty good on top....Looking forward to seeing dyno and in-car results on this one!

 

Is this your intake?: If so, I think that motor of yours is going to make plenty of grunt, and rev pretty good on top....Looking forward to seeing dyno and in-car results on this one!
View attachment 711232

Yes that is mine, done by Chopper Scott. I will have it soon!

 

I like power valves on both ends of street driven carbs

 

I like them in the front for street driving for sure!! I tried without them before in the front and didn't like it!! I might have to try using them in the rear!! And taking Jet out of the rear!!

 

Thanks to chopper Scott for a perfect port match and a job well done.

 

curious ... Have you measured the runner opening area - Sq inches ?

 

I have two 650s on my 370 SBC nitrous motor, it run great, done by mark whitener

 

Mark built me a 750 for a 331 I built a few years back. He don’t seem to be as active now.

 

Please, please don't remove the Power valves on a new engine. Especially one that's to be street driven.

 

Mine was dyno’d with them plugged, then street driven a fair bit, and it’s worked great. The throttle response is great. What’s your primary concern with this situation?
I’m not being a smartass, I just want to know what the concern is. With the power valves it ran so rich it stank us right out of the dyno room, so my engine builder (an old Modified Production/ Stock eliminator/ SuperStock racer/ builder that’s done contract work for GM on SS/GT builds and r&d, as well as winning with almost every vehicle/ engine he lays his mitts on) removed the pv’s, installed plugs, jetted accordingly, and it immediately ran clean as a whistle, idled strong, was extremely crisp, and throttle response was honestly amazing compared to what all the cruise night “experts” keep trying to tell us a tunnel ram motor is supposed to be.
I honestly wouldn’t change a thing…..unless it’s to add Cleveland high-port heads and a Boss 302 tunnel ram….and maybe an Induction Solutions Saturday night special plate kit for special occasions.😁

 

Not all power valves behave the same even the ones that are the same rating. All your builder did was eliminate one variable that may have been problematic. Doesn't mean that removing the power valves from street or circle track engines is the preferred approach.

 

Either too high a vac number, or a blown diaphragm.

Or a leak at the gasket, or just way too much jet. Clearly something was just wrong.

 

curious ... Have you measured the runner opening area - Sq inches ?

2.850 x 1.800

 

I'm building a very similar combo. 427,TFS 11R 227s and EFI, TKX also. It's going in a 31 Model A. Haven't port matched the intake yet,but it's on my list.