305 Head question [Archive] - Chevelle Tech

: 305 Head question


73Malibu
Jul 18th, 99, 5:33 AM
I have the early 434 casting heads on my 305, when I had them rebuilt I measured the valves at 1.5" Exhaust and about 1.92" Intake. At that time I had read somewere in the library that both the 305 and 350 for those years (77) both had the 1.94/1.5 combo. I recently got a nice book Chevrolet Small Block V-8 ID Guide by Pierre Lafontane, which has tons of info, VIN tag and stamping Suffix etc, saved me from buying a 73 Impala with a 400 emissions sticker, but a 145 hp 350.
Anyways, supposedly all 305 heads had 1.72" intakes except for 80 up 4 barrel engines 1.84" Was I retarded when I measured the valves, I measured the widest point of the face on a metal drafting ruler with 1/64" marks, The intakes were nearly 2" wide as I recall (10 years ago) 1.72's should have been obviously smaller??? or did someone stuff in 350 intakes previously?? This has been puzzling me for sometime now.

Frank


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Harley
Jul 18th, 99, 6:21 AM
Read your post and couldn't remember, so I troted out and checked my "wood pile" of 305 stuff and there on top was a set with 1.94 dia. valves. The problem with 1.94s in the small chamber of the 305 was excessive shrouding so I doubt that 1.94s are much better than the 1.84s.
Harley

plain 69
Jul 18th, 99, 7:13 AM
Maybe somebody put 350 heads on it because the 305's were cracked or something.

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Malibu 307 (aka 406 smblk)
69 SS 396(aka 454)
Wolf in sheeps skin

Harley
Jul 18th, 99, 8:23 AM
Head casting no# 354434= 75-79 262/267/305.
Ref. Mortec.
Harley

73Malibu
Jul 19th, 99, 1:23 PM
Harley, you were correct about the full casting #, the date codes were J156 and J276 Both correct to be the original heads for the motor. When I tore the motor down, It appeared all original, no cyl wear still had crosshatch and no ridge, Had a good cam, the factory ones were soft, that had been changed. I wonder why the LG3 was not listed with 1.94 intakes??

Frank

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