Thread: 350 SB stock torque rating

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what is the hp and torque ratings for 69-80 350 SB 2brl out of a full size car?

casting # 3970010

thats all I know for now.

346260 intake.

73-77 chevelle, caprice(full size), camaro

with an EGR valve.

Well you may not like this but here is the data from the 1982 Chilton's Auto Repair Manual for Chevelle 350 V8 w 2 bbl:

Year HP@rpm Torque@rpm(ft. lb.)
1975 145@3800 250@2200
'76-'77 145@3800 250@2200

'78-'79 170@3800 270@2400 350 V8 w 4 bbl

Corvette w 4 bbl (from Chilton's 1963-1982 Repair Manual)
1969 300@4800 380@3200
1970 300@4800 380@3200
1971 270@4800 360@3200
1972 200@4400 300@2800
1973 190@4400 270@2800
1974 195@4400 275@2800
'75-'76* 165@3800 255@2400
1977 180@4000 270@2400
1978 185@4000 280@2400
1979 195@4000 285@3200
1980 180@4200 255@2000
1981 190@4200 280@1600
1982 200@4200 285@2800 (TBI)

In each case I have listed the LOWEST rating for a 350 V8; there were of course high performance optional engines closer to 350 HP. There are two main effects here. First around 1971 GM changed the way it reported H.P. from flywheel w/o accessories to with accessories so that lowering is somewhat artificial. The second factor is more serious in that the Corvettes were detuned for the gasoline embargo experienced in 1974 for a few years. I have put an * at 1976 because I bought a '76 Corvette (2-bolt) thinking it would be higher performance from a Corvette only to learn that was the lowest H.P. Corvette! Still with a cam similar to that in the 300 H.P. 327, flat top pistons giving a C.R. of about 9.2:1 with shaved 882 heads, headers, and an Edelbrock Performer manifold I hope to get at least 250 real H.P. and with 1.6 ratio rockers on the exhaust valves I hope to get about 370 ft. lb. or more in torque at low rpm, but who knows until I get it to a dyno, if ever. Maybe you should invest in a Chilton's Repair Manual, it has a lot of this sort of stuff in it.


If you want some encouragement take a look at Ryan's Dyno site:

http://www.ryanscarpage.50megs.com/combos1.html

With a small cam or just a stock cam it looks like 1.6 ratio rockers on the EXHAUST valves can really improve torque, I hope so!

This exercise has been partly for my own understanding in relating to my frozen brain memories of flathead Ford V8s:

'42-'48 95@3500 HP@rpm 177@1700 ft. lb. @rpm stock
'42-'48 112@3600 HP@rpm 200@2100 ft. lb. @rpm modified

These values are taken from a graph given in the Speed and Power Handbook, Newhouse Automotive Industries, 1952, p56 and the modified data for the flathead is for just higher C.R. of 8.5:1 and dual Stromberg carbs. The actual data from Ford may be slightly different, but you can see that even a stock SBC 350 is far more powerful than a slightly modified flathead common on the street in the 1950s and any rodder with 8.5 heads and a dual intake in 1955 would have thought it was souped up to about 3/4 race, so the Corvette 165 H.P. motor looks pretty good to me and 250 H.P. should be great for a retired guy like me!

Don Shillady
Retired Scientist/teen rodder

If that motor in my grandpas truck (engine from a car) cranks out 270lbft. and feel that powerful.

man my performance 350 sucked. 270 cam, 600 eddy, wieand intake, 882 heads, flat top pistons.

Well I am not sure what you mean, but gearing is important and most high performance engines are set up for high rpm, high stall converters and tall rear gears, but still if you had a 270 degree cam that is not really set up for very high rpm and you should have had good power. I would think a truck would have a 3.55 or 3.70 rear gear and again that truck should have run good! After you posted, I edited my post and added some data for Ford flatheads of a type common in my high school days and by comparison the SBC-350 looks fantastic even with 882 heads which were part of the detuning and improving low rpm torque. I also remember my Dad's 1969 Chevelle and I recall that I thought it was very dangerous and the accelerator pedal spring should have been stronger. That '69 Chevelle was "wickedly fast" and if I get that performance with my 2500 pound 'glass '29 Ford roadster that will be all my heart can take at my age, but I can't wait!

Don Shillady
Retired Scientist/teen rodder

Well somehow I hit the submit button twice, but no big deal. I enjoyed the task of looking up the comparison of the SBC 350 and the 59AB Ford Flathead. I know you can get about 270 H.P. from a flathead with a stoker crank, porting and relieving and dual or quad intake, but first you have to find a flathead block that is useable and that is becoming more difficult as time goes by and maybe in 10 years or so the SBC 350 will be scarce, but I doubt it, there are so very many 350s that it ought to be available at least until we are all running electric hybrids!

Don Shillady
Retired Scientist/teen rodder