I currently bought a 71' Buey 'lark with a 70' 455 from an Electra. I guess my question is .....how far do I need to go to match the GSX 455 HP ratings with this model engine? I figure the stage heads and maybe a beefier cam/lifter set, but, I've been told the Electra still put out some impressive HP and low end torque for a "grocery getter"! Anyone with some specs on this engine? I'd appreciate anything I can build on!!
This 455 is a strong one and it shifts beautifully! The only thing to make it streetable was to replace the front springs from the 350 SB (originally) to GS springs and front end bushings! Man, what a difference! It still has build sheet and manual in glove box and I plan to eventually build a good 350 to bring it back to original, but, I might as well have some fun with the BB before then, huh? Thanks alot in advance!!!!
jammon455

specs from Petersen's Big Book of Auto Repair - 1983

1971 was the first year that gm took a big hit in compression ratios. all the buicks for this year are 8.5:1
350cu was available in the skylark with 260hp / 360 lbft of torque and the base was 230hp / 350 lbft.

455cu Stage 1 had 345hp / 460 lbft while the base bbb was 315hp / 450 lbft

1970 455cu compression ratio's were all 10:1 except for the GSX engine which was 10.5:1
base engine had 350hp / 510 lbft of torque but there's only one engine listed for the electra and that shows 370hp / 510 lbft which is the max for that year.

basically, any 1970 engine is better than a 71 engine. in fact, all of the 67-69 430's have better power specs than the 71-76 455's primarily because of the reduction in compression ratio although converting to the SAE power rating and emissions equipment in later years did play a part.

if for any reason you should want to 'get rid of' that 455 engine be sure and let me know. :D

rocker ratio for all years of the 455 and the 350 for 1970 was 1.55

the 70 455s had two cams:
valve lift of 387int / 459exh or
valve lift of 490int / 490exh

the 71 455 had an intermediate option of
valve lift of 430int / 468exh if you didn't want to go quite so aggressive

I plan to drive my 455 bb equipped 1970 skylark evryday. Do I need to change anything to make it handle todays unleaded fuel? Some folks told me to have the valves hardened? Is this true? If so is that all?

run avgas and you won't have to worry about it. tongue.gif

check this thread. http://www.v8buick.com/showthread.php?s=&threadid=42675

that's really only a great idea if you've got one of the 10:1 compression engines. if you've got a 71 or later engine you could probably get by with fuel additive.

I have a 9 to 1 455 in my 37 Buick street rod and it runs just fine on 87 octane. My 72 GS has a 10 1/2 to 1 and it requires 92-93 octane. Additives are not neccesary in a Buick engine as the nickel content in the block was high enough to stop valve recession. I have never used an additive, and have run over 100,000 miles on one engine without seeing any recession.