my brother picked up these heads for free as they were about to be binned . the number on one of the heads is MP 121861 with 73 stamped on the manifold side . are they from a 1973 350v8 ? and are the 72 heads & 73 interchangeable ? tkx
There the same?.....hum, so whats the difference between a say 68 350GS engine and the 1978 350 I have......this is interesting. uzzled:
this will give you an idea of the CC and compression ratio for each year. The 350 for each is highlighted. http://buick.viragotech.com/BUI-68-82.rtf
77 & 80 heads have the biggest CC of all years but crap for compression. Odd as they did it in 77, then stopped, then went back in 80. Which is tits for me and my 80 350. I got CC and just need to get the compression up and it should start breaking drive train parts.
I have been reading this 73 head thing and no one has mentioned or dont know that the 73 head has a water passage that is not on the 72 and earlier heads. If you have a 72 block the 73 head will leak water into the lifter vally. Found this out the bard way 15 years or so ago. Just look at your old heads and compare to the 73 and between the center cylenders there will be 2 holes that are not in 72 and earlier. Dan
I have heard this also. Jim Burek told this to me a while back. He stated that the water passage is oblong and must be ground to a circle in order to insert a plug so that you can use it on a earlier block. Maybe Jim can elaborate on the diffrence,
Whoa! That list is saying that rocker ratios were all over the map from 1.50 to 1.60! I had never heard that before!
This is correct. In 73 Buick changed the water passages and added 2 more on the head. They are oval shaped which makes them more difficult to plug than a round hole. I simply round them out so either a press in expansion plug can go in or so they can be tapped and threaded plugs installed. Thes later head wil leak water into the pan if used on 72 or older blocks withou the holes plugged. Jim Burek Hey Phil, did Patton tell you he heard his engine run today? p
I have no responsibility for the accuracy. If you check the other makes folders I have them for most all cars.
does that viragotech say that the compression ratio is 10.25:1 for a 72 350 ? i thought it was less . what is the compression ratio for a stock 72gs 350 4v ? i have seen anywhere from 8.5;1 --> 10.25:1 .
Jim, It sounded as if you and Patton were in heaven yesterday. He said his motor sounded like a pro stock motor over the telephone. :3gears:
Per GM corporate mandate all engines 71-later were to have compression no greater than 8.5:1 to accomodate unleaded gas and the introduction of catalytic converters(those appeared in 75). By lowering compression, you increase exhaust gas temperature which was required by the rudimentary catalytic converters to remove harmful exhaust, NOx and CO. :Smarty:
Phil, really, it's just a pup, nothing radical by any stretch. I guess over the phone it sounded pretty wicked, especially when holding the phone up right behind the exhaust. Jim
Although you amplified the sound by using the old Dyno/phone/manifold trick. Patton was happy just to hear the motor run again.... Don't get him to excited.... It could be dangerous... :beer
It sounded more Top Fuelish than Pro Stockish :Brow: :Brow: Darn car isn't going to know what to do with that motor in it!!! Thanks for the sound bite Jim!! :TU:
I should a run it without the muflers, that would sound pretty good. It's only a baby 230/240 cam. Jim
