Help Identify this I6

[jeffnohio]

Hey I Put this in the engine section also but thought I might get more help from this section also.. I need points but not sure what motor I have .. I can get the engine cast numbers but it is out at my folks and want to pick up points on the way with out having to make 2 trips..

Here is a copy of the post and orginal link http://67-72chevytrucks.com/vboard/s...=1#post2417479

I have a 67 3/4 ton GMC with inline 6 with non intergrated intake and exhaust manifold and single barrel carb,.. the motor has 2 engine covers on the passenger side.. Transmission is a 4 speed granny.. I am needing to buy points for it but not sure what I have.. is there any way to tell right off the bat with out running engine block numbers? Here is a picture of it while I was replacing the intake exhaust gasket..

THank you guys for any help on this..


After doing more searching on here I found this link http://67-72chevytrucks.com/vboard/s...ad.php?t=98969 and basically boils down to the lifter plate/Pushrod covers size to determin what cu. will be from an outside visual ident.

You should be able to identify the big vs. small block by how big the pushrod covers are on the side. If they are smaller than 5" then its a 250 or smaller and if its bigger then its a 292. If it has an intregal head intake and exhaust then its an 80's model.

I just wonder if this is a width measurement or hight measurement mine is 4 & 1/2 tall I am assuming it is the hight.. so this is more than likely a 250 I6 ????

[john]

Theres a couple of pics in this thread that will help.


http://67-72chevytrucks.com/vboard/s...ad.php?t=15807

[jeffnohio]

Hey John Thanks a bunch .. I have a 250 for sure ,..

[Brad]

Yep, either a 230 or a 250 which would take the same part. I'm almost positive it's a 250 based on what it's in.

[jeffnohio]

Hey Brad I see in your sig line your 250 is pretty decked out .. Not to venture off topic but how is the gas milage on that compared to a stock set up? I plan on keeping the six in mine but would like to convert over to HEI and header and something with smaller primaries on the carb

[Brad]

Why I'm glad you asked. I just wrote about that here:
http://67-72chevytrucks.com/vboard/s...d.php?t=208202

As far as converting to HEI, DO IT! It's the single most important thing you can do for that engine. That should be your first priority.