I just need some general info on the '70 GS350 motors. What parts were specific to the high compression motors? (Comparing the '70 GS350 to any '70-74 or so 350 block). I'm going to be looking for another block and need to know what all needs to come from a GS motor to keep the compression and correct performance. Thanks in advance.:TU:
chris the pistons are specific to the setup. smaller dished piston. everything else is pretty much the same. and maybe a cam (not sure on this one)
I thought maybe the heads were different, but after looking on the net a little bit just now I see that all 350 heads were the same. So I guess differences would have only included Pistons, carb, and cam? I guess that would make sense.
70 gs 350 i was told the distrubuter is recurved by gm for hi comp also the 020 thick steel shim head gaskets which are worth .5 comp andyo No:
The 4 barrel carbs were the same on all 350s depending on year and trans. You can verify here. So it looks like carb was not GS specific. Unles your GS was standard trans equipped? http://buickperformance.com/qjet.html Korrie
It was my understanding that you can not use the 72 up heads on a 70-71 block without modification. Therefore whatever heads that you are using may dictate what block you choose.
Chris, the 68-70 heads have a smaller CC than the 71 and up. it's not much, but it will lower the CR a little.
Ok, well I will be using '70 GS heads, so if there is a difference in CCs they should be the smaller of the line and raise compression. Sounds like I should be safe with any 68-72 block?
Chris C.- do you know what the CC diffrence is between the post 71 and 70. I would like to see numbers. just curious. I have heard of this before just have not seen the numbers. I assume it will be no more than 2 or 3 cc's diffrence at most. thanks.
i've heard the CC diffrence though is in the valve design not head design. the 71 and later valves have more of a dish to them than the 70 ones. nate