I am updating my carb to a 3310 :D
but right now my cast iron intake is a spread bore. I am hoping to get a stealth or a rpm and wanted to know if there is an advantage to one or the other?

Performance or daily driving advantage?

Wouldn't the squarebore get poorer milage?

I have a spreadbore on my 350 and my dad has a squarebore on his 454. Since its mechanical secondaries having smaller primaries and larger secondaries seems to work better for me.

I don't really care about mileage so perf wise?

My dad has a mild build on his 468 (around 430-450 HP) and the 650 squarebore doesn't seem to have any trouble feeding it right now...

surely someone who really knows about this stuff will chime in

The 3310 is not the hot set-up. It is very popular though. That carb and it's electric choke brother both use the crappy straight boosters, and of course there is the secondary metering plate to contend with.

I think you'd be better off with a Speed Demon (I have no experience with them, but the advertising looks good) or a different Holley model, preferably a 4150 series.

The RPM manifold gets all the press now, but there's nothing wrong with the Stealth. I wanted to have the option of running a spread bore OR a straight bore carb on my 454 boat, so I bought the Performer RPM Q-Jet. There's no BBC Stealth for a spread bore carb.

Schurkey- Is there a v/s 4150 series carb? I see some reconditioned ones but I don't know if I like that idea.

Originally posted by Schurkey:The 3310 is not the hot set-up..I don't know-I beg to differ,seems to work fine for my combo smile.gif graemlins/thumbsup.gif
..and my combo is far from optimized and dialed in.Hooks good though ;)

Stealth or RPM,doesn't really matter.
You'd be hard pressed to find any ET difference between the 2,and even if you don't go to the track,that translates into transparent "seat of the pants" on the street between them.Its your choice.
On the recondtioned carb,my 3310 is exactly that.I paid $179 for it from Scoggin-Dickey..same warranty as new.I belive Jegs and Summit sells them now too,but they cost more than $179,but are cheaper than brand new.And you can't tell the difference as fars as new vs. recond/rebuilt
And yes,a 3310 is a 4150

The 3310-1 is a 4150 series carb with the secondary metering block. It is rated at 780 cfm.

All others 3310 -2 -3... are the 4160 series with a non-adjustable secondary metering plate. These are all rated at 750 cfm. These can be converted to use the secondary metering block as well.

Sam

sam/4speed thank you, but....
Any thoughts on the square or spread bore?

Well, if you are going to use the 3310 (squarebore carb), you want to use a squarebore manifold.
If you get end up finding a speadbore manifold to use, then an adapter plate can be used to fit the 3310 on that type of manifold.

Does this answer your question, or did I miss something completely?

Sam

I am wondering if there is any benefit one way or the other, the manifold can be had either way so I thought as long as I could choose I might as well get the best if there is a difference.

if you have or going with a square bore carb go with a square bore intake. one less part you have to buy (spacer/adapter). is there a benifit either way no. one of the mags did a test and didnt see anything on the dyno. on the rpm intake......they thought the spreadbore intake might provide alittle more plenuim under the square bore carb for alittle more top end power but nothing was found.

A little history if I may. The early 0-3310's were 780 CFM 4150 carbs with downleg boosters.Holley soon discovered that the majority of the aftermarket 0-3310's were actually being used on small blocks and not the big blocks that they were designed for.

So after discovering this and hearing a fair amount of complaints due mainly to the carb being used extensively in the wrong applications ( IE 283 /327/350 small blocks with L79 cams ,PG /TH350 and 2.73 or 3.08 gears )..... Holley decided to change the carbs some and added the straight boosters and in attempt to make it abit less expensive they converted it to 4160 with the secondary plate... The straight boosters would pull a harder signal and activate abit earlier than the higher capacity
downleg boosters would and therefore actually make the carb more responsive in the lower and mid power ranges that these carbs were increasingly used on.By makeing it a 4160 with the secondary plate it allowed an astute hot rodder to change not only the secondary main circuit but the secondary idle circuit as well.... The problem was that very few people ever took advantage of this and replaced the plates with blocks so they could change jets... the average person simply understood jetting better than they understood the drilled restrictions in a plate.

Cant really blame them as Holley never really did much to promote or even educate people on how to use the plates effectively..... and heck the metering blocks simply made the carb look bigger and badder.... that reason alone accounted for alot of the conversion to 4150.

Properly set up they are very usefull and forgiving carbs.... improperly setup they can be just as tempermental as any other improperly setup or mis applied carb.

69LS1-thanks for the history 101, man I feel like I am back in school,lots to learn.
Dennis- thanks as well.
Between the two of you I got it I hope.
For a guy who is not going to do a lot of futzin', am I to understand either the 4150/60 model will do what I want?