Thread: SBC 350 rebuild to run on 87 octane, Daily Driver?

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I am to take the stock engine to have it rebuilt here in town. I am a little confused though on what I need done. I am looking to keep the engine running on 87 octane but squeeze what I can out of it. The guy up at the shop said they would resurface the heads and install flat tops along with a mellings MTC-1 cam and i would still be able to run 87 octane.
cam specs for MTC-1
Cam Style Hydraulic flat tappet
Basic Operating RPM Range Idle-4,500
Intake Duration at 050 inch Lift 204
Exhaust Duration at 050 inch Lift 214
Duration at 050 inch Lift 204 int./214 exh.
Advertised Intake Duration 278
Advertised Exhaust Duration 288
Advertised Duration 278 int./288 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.420 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.433 in.
Valve Lift with Factory Rocker Arm Ratio 0.420 int./0.433 exh.
Lobe Separation (degrees) 112
Computer-Controlled Compatible No



I am reading that I need to stay around 8.5-8.75CR to stay with 87 octane. My current compression is 8.50 to 1 or a little under with the stock engine.

My current set up is with this as a daily driver.

84 c-10 with a quadrajet
rear end ratio, 2.73
truck weight , 4000Lbs
trans, turbo 350
tires , 31" tall
stock exhaust system, 2 pipes into one then cat and muffler.

Engine Name: 350 LM1
Horsepower: 249 HP @ 5,000 RPM
Torque: 304 Ft/Lbs @ 3,500 RPM
Compression Ratio: 8.50 to 1
Block: 4 – Bolt, 2 Piece Rear Seal, 4.000” Bore
Crankshaft: Cast Nodular 3.480” Stroke
Heads: Cast Iron, 76cc
Valves: 1.940” / 1.500”
Camshaft lift: 0.390” / 0.410” Hydraulic
Duration @ 0.050”: 195° / 202°

A little confused on which set up would be best.

if a TBI GM engine you need to use a very small stock cam the MAp sensor will not like any cam and needs a clean idle . cutting the heads as not to big of a deal but knowing were you are know by CC the heads and getting the deck of the block were it needs to be pistons most of the time are way down in the hole not good your CR may be less or more on evey engine this needs to be looked over very carefuly

sorry bout that , its a 84 c-10 with a quadrajet. Thanks

did the machine shop give you a print out on any numbers .i work with Tq and with RPM your going to be at most of the time as for your CR and gas grade you can get away with more CR at times with getting the piston to block deck heigth right and knowing what dynamic CR you have will let you know what grade of gas you may get away with . i like to work all this out for my customer s

ya, no numbers , I guess that the confusing part

maching the engine is one part but making every thing work is another.i would watch the CR if under heavy load all the time with lower grade gas can be done if somone is willing to do the work . i would match cam and cr to rpm and use the V teck heads or a after market iron head with new intake for the new heads if not that buy a Gm crate engine