yamahaguy91

is the holley 750 DP to big for a 355 with a mild cam??? or should i just stick with a 600?

86'Bowtie

I'm running a 750cfm Holley DP on my 355.
No, it's not too much carb, going w/ like an 850 or higher maybe too much. At 750cfm you should be just right.DUECE

ljnowell

not a holley guy, but i thought all DP'ers were mechanical secondaries?

86'Bowtie

Your right
At the time my friend was telling me about his Street Avenger.
Sorry, I was confused. Still 750DP hands down.

Stekman

Define "mild cam." What are your specs. Ive run a 650 DP on my 355 and i absolulty LOVED it.

I dont think you will see that much gain in a 750 over a 650.

racindaelky78

mmmmmmm double pumper,mech secondaries are sweet, you should have no problems with the 750 DP on the street,but make sure you tune that carb and that secondary arm if you plan on getting secondary response out of the thing before factory preset,i also suggest doing this at the track,i bent mine to open at 1/2 throttle and use all 4 barrels to WOT.

five7kid

iTrader: (14)

The chart on this page http://www.holley.com/HiOctn/TechSer...nfo/P225A.html shows how big a DP you can put on your engine based on the minimum RPMs at which you'll go WOT (typically stall speed).

For a 350, you don't want a 750 DP if you'll floor it at anything below ~1500 RPMs.

f-crazy

iTrader: (-1)

thats exactly right...there will be MAYBE a 10 HP peak gain...
im runnin a 650 DP on my 350, and ill tell ya, the MF'er is VERY crisp
and besides, theres always the main body for that 650..

yamahaguy91

mild cam i mean somthing like the extreme energy 274. the reason i ask is i can get a 750 DP for $150.00 and thats alot cheaper then a new one.

five7kid

iTrader: (14)

I'm not sure I'd define an XE274 as "mild", especially for a stock converter. You're going to need at least 2500 stall, if not more.

With proper stall, a 750 DP will be fine.

yamahaguy91

well i have the B&M 2400 TC so do you think i should jump on the 750 or just spend the cash for the 600 this car will mostly see street and very little strip

f-crazy

iTrader: (-1)

IMO id wouldnt go any bigger then a 650...and i wouldnt advise getting a used carb, no matter if it was "just rebuilt"...If your running mostly street like me then a 650 is the way to go..
you wont see but a minimal PEAK gain with a 750 and i bet itll be a bit "soft" down low...

yamahaguy91

well thanks guys i think i will just spend the money on a 600 or 650.

njspder

355cid revving to 6000rpm peak = 616cfm.
general rule of thumb is to use the next available carb size above your total air volume, so a 650 would be great for your motor.
go to www.prestage.com to see the formulas for figuring carb size.

later
tim

f-crazy

iTrader: (-1)

go with a 650...the gains over a 600 will be more substantial, then a 750 over a 650....

and with a 650 you can get a bigger mainbody in the furture so u dont have to buy another carb..the main body is "rated" at 750, but it flows closer to 800

five7kid

iTrader: (14)

The 2400 stall isn't a carb issue, it's a cam issue.

As previously stated, a 750 will be find down to around 1500 RPMs, and you're well above that.

If you had a 650, I'd say run it. But, only you can decide what you could do with the extra $250 you won't have by buying a new 650 vs. the used 750 you can get.