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so im picking up a 71 olds 350/trans for 150 bux..

im just wondering what the difference between the 71 non smogger -and my 74 smogger...

is it the heads, and intake, cam and maybe pistons (74 has dish, does 71 have flat?)... if so whats the diffrence between the heads. ive ported my 74 heads out, and converted to adjustable rollor rockers. wondering wich heads i should use..

i just i cant really find much info on it.
 

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Olds motors

so im picking up a 71 olds 350/trans for 150 bux..

im just wondering what the difference between the 71 non smogger -and my 74 smogger...

is it the heads, and intake, cam and maybe pistons (74 has dish, does 71 have flat?)... if so whats the diffrence between the heads. ive ported my 74 heads out, and converted to adjustable rollor rockers. wondering wich heads i should use..

i just i cant really find much info on it.
I have a friend that is an olds guy. he says the 4 barell 350's had more compresion and biger cams than the 2 barell vrs., that is second hand info. I would emagine a 71 would have better compresion than a 74
 

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so im picking up a 71 olds 350/trans for 150 bux..

im just wondering what the difference between the 71 non smogger -and my 74 smogger...

is it the heads, and intake, cam and maybe pistons (74 has dish, does 71 have flat?)... if so whats the diffrence between the heads. ive ported my 74 heads out, and converted to adjustable rollor rockers. wondering wich heads i should use..

i just i cant really find much info on it.
Results are directly proportional to the effort you put in.

One trip to the public library would find all you need, but I googled this in about 5 minutes:

442.com said:
Olds 350s come in a few varieties:

1968 - 1972: Smaller combustion chambers, strong blocks, possibility of Nodular Iron cranks (a close second to the forged cranks that the 330's used). Four-speed 4-bbl engines had pretty decent camshafts. No EGR. Of course, if you get a W-31, you've got a pretty great engine right from the factory. The '68-'69 heads used a smaller exhaust valve than the later units. The high-compression pistons will make any of these a high-compression motor. 7/16" head bolts.

1973 - 1976: Larger combustion chambers, small intake and exhaust valves. EGR intakes, but the #8 heads were not too restrictive (compared to later units). Block is still relatively strong, with solid main webs. No more nodular iron crankshafts, but HEI ignitions on the later units are the best street setup. You need earlier heads to get high compression, even with high-compression pistons. 7/16" head bolts.

1977 - 1980: Large combustion chambers, small ports, EGR, low compression. They did, however, have ½" head bolts (in common with the 403's and diesel 350's), though the windowed mains on the block make these the weakest engines to start a performance rebuild from. In reality, however, you're not likely to blow out the bottom end of this motor on the street below 6000 RPM.
Mike Bloomer (442.com) said:
In 1970, the 350's had 9.0 CR with a 64cc head. In 1971 the CR dropped to 8.2 with the same cc. This was accomplished with a "dish" in the piston. This carried over until 1973 when the CR dropped again to 8.0 BUT with a 79cc head. This means that the dish was gone but the large chambers in the head caused a further drop in CR. Going from the stock 79cc heads to the earlier 64cc will bring the CR up to around 9.2 but with the thicker head gaskets than stock you can figure on about 9.0:1 "true" CR. This will definitely wake up that motor and with a cam, 4bbl, and dual exhaust you should get 250 HP net easily as long as the bottom end is in good shape.
 
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