Team Chevelle banner
1 - 13 of 13 Posts

·
Premium Member
Joined
·
3,273 Posts
Discussion Starter · #1 ·
What Carb and what size do you recomend for 350 bored out to 355 cu. in. for this cam and 1 3/4inch headers? Will be 4sp trans. Looking at a 670 cfm Holley 80670. Will be street use for the most part with 4 trips or so to the track per year.

Duration @ .006
In. 276 deg.
Ex. 282 deg.
Duration @ .050
In. 223 deg
Ex. 320 deg.
Lobe Lift
In. 314
Ex. 320
Valve Lift
In. 470
Ex. 480
Valve Lash
In. Hyd.
Ex. Hyd.
In. C/L 104 In. Open 34 In. Close 62 @ .006 Tap. Hgt.
Ex. C/L 116 Ex. Open 77 Ex. Close 25 @ .006 Tap Hgt.
Lobe Separation
110
Valve Spring Seat Pressure
80/90
Valve Spring Open Pressure
280/290
 

·
Registered
Joined
·
2,049 Posts
670 is perfect , if you dont already have headers get the 1 5/8 , the 1 3/4 are overkill! nice little 355 combo with 9.5-10.1 compression.
 

·
Premium Member
Joined
·
3,536 Posts
not with a 4 speed, it will create a little stumble after you shift without the right spring.

Stumble is not the secondary spring, it would be the right pump cam and squirter, that applies to both vacuum and mechanical secondary carbs. I have 0 stumble with the 770, and 3.73 posi with 3400 stall, no issues what so ever.....
 

·
In Memoriam
66 El Camino 57 Chevy pickup 2004 Tahoe
Joined
·
29,419 Posts
I agree with Walter on that deal about the hesitation. I've seen this remark a couple times lately, don't know where it's coming from. I haven't had this experience with a couple hundred vac sec carbs over the last 30 years or so.

IMO you'd be doing well with a Holley SA670 and 1&5/8 headers. 1.75 are too big.
 

·
Registered
Joined
·
7,729 Posts
I would go with the 770 Street Avenger, if you do upgrade to a 383 or a 406 lets say that carb would be perfect with that set up too.

Dave
 

·
Premium Member
Joined
·
6,426 Posts
I would go with the holley street avenger 670 vac secondary its good to 400+ hp on the street very tunable.
I ran one on my old 468CI on the car in my sig and it feed that 400hp 8.8:1 comp motor no problem suprised alot of ppl that at the track I ran an old holley 600cfm vac secondary marine carb on an open plane intake and ran the 12.73 at 104mph. I never got it to the track with the 670 S/A but it ran fine on the street it it will feed a low comp BBC I dont see any reason it wont feed your 355. just my 2 cents
 

·
Premium Member
Joined
·
3,273 Posts
Discussion Starter · #13 ·
I agree with Walter on that deal about the hesitation. I've seen this remark a couple times lately, don't know where it's coming from. I haven't had this experience with a couple hundred vac sec carbs over the last 30 years or so.

IMO you'd be doing well with a Holley SA670 and 1&5/8 headers. 1.75 are too big.
Thanks, Tom will go with that setup.:D
 
1 - 13 of 13 Posts
Top