| |
Click on image for the lowdown. 
====
| | | Forums66 Topics128,049 Posts1,055,652 Members48,426 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Feb 2012 Posts: 112 'Bolter | | 'Bolter Joined: Feb 2012 Posts: 112 | I am tearing down a 1952-54 gmc 302. The cam installed is no. 2136000 which my searches show is for a 52-54 270. I have searched and can not find specs on this cam or if it is different from correct 302 cam. Does anyone know if these cams have diff or same specs?
Old Truck addict
1950 chevy 1 ton napco
1956 gmc 1 ton dually napco
1954 chevy 3/4 ton napco
1957 gmc civil defense napco panel
| | | | | Joined: Jun 2011 Posts: 1,901 Shop Shark | | Shop Shark Joined: Jun 2011 Posts: 1,901 | I could be wrong but my understanding is the only difference between a 270 and 302 is piston diameter. So they can uae samw cam.
Give me ambiguity
or give me something else
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Inliners show several 270 and 302 cams. However, they also show other cams that work on both the 270 and 302 (your cam might work): 1946-1952 270 2136000 not used on a 302 1953 270 2191529 1954 270 2191529 1954 270 2192486 1952-1954 302 2192486 1955-1963 270 2326722 1955-1962 302 2326722 http://www.inliners.org/casting/numgame.html | | | | | Joined: Feb 2012 Posts: 112 'Bolter | | 'Bolter Joined: Feb 2012 Posts: 112 | I found the different cam casting numbers but was looking to see if there are any specs to see if lift/duration are different between cams.. Is there a "best" one to use for performance?
Old Truck addict
1950 chevy 1 ton napco
1956 gmc 1 ton dually napco
1954 chevy 3/4 ton napco
1957 gmc civil defense napco panel
| | | | | Joined: Jan 2008 Posts: 4,961 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,961 | Casting numbers are not necessarily part numbers. The June 1957 revision of the GMC master parts book lists a p/n 2193486 to fit all of the 228-302 series blocks. The January 1962 revision shows a 2326722 to fit 270 and 302 like Tim posted. They will all interchange, but you need a distributor designed for cast on the cast iron cam and a distributor designed for steel on the steel cam. There is probably no noticeable difference. If you are looking for performance, you need to look at an aftermarket cam designed for performance. | | | | | Joined: Apr 2005 Posts: 2,832 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 2,832 | You can check out the cams with just a degree wheel and dial indicator with an inch of travel. Checking TOTAL duration and TOTAL lift is quick and easy. On short duration cams where first movement of the indicator is easy to see it is a fair ballpark comparison. Put the cam in "V" blocks and fasten a degree wheel to the cam. Rig up a pointer for the degree wheel. With the indicator on an intake lobe rotate through 360 degrees and note where the the needle on the indicator starts and stops moving on the degree wheel. Same on exhaust lobe. Also note the maximum lift shone on the indicator. Then do other cam and compare. Probably both are very close. Now to "spec out" a cam we're talking a whole new ball game which is not quick. This gives opening times, closing times, overlap, center line, etc.
Evan
| | |
|
|
| |
