Camshaft

[Kidd-7]

This winter I'm going to work on the engine a little. I have headers and an intake manifold that I'm going to clean up and install. Need to find a good 4-barrel; but the question is about a new cam. I know nothing about cams. What do I look for? The truck is just a cruiser so nothing extreme. Its a 71 C-10 w/ a 307 stock 2B Rochester. Any input would be great. Thanks.

[MikeB]

A good step up from stock is the very popular 204/214 cam. Edelbrock sells a cam and lifter kit as their P/N 2102. http://www.summitracing.com/parts/EDL-2102/

Summit Racing's version is SUM-K1102. http://www.summitracing.com/parts/SUM-K1102/

My guess is the Edelbrock lifters are better.

You can use stock valve springs with these cams, assuming they are in good shape, and you don't have to worry about valve-to-piston clearance. I would definitely install a new timing chain set.

A good 4bbl carb would be a 500 CFM Edelbrock Performer. http://www.summitracing.com/parts/EDL-1403/ The 1404 is the manual choke version.

A Holley 390 will also work well on your 307. http://www.summitracing.com/parts/HLY-0-8007/ as will a Barry Grant 525 CFM Road Demon Jr. http://www.jegs.com/i/Barry%20Grant/...0002/-1?CT=999

Have fun! And remember, when it comes to a mild 307 with stock heads, bigger is most definitely NOT better.

[hugger6933]

just don't get to big! the truck will be a lot more fun to drive if the cam is chosen wisely. Also remember when someone says I run bla bla bla that is probably in a 350 and those can take more cam than your 307. Like sated earlier a matched set for your intake is always a good chioce. Those guys at the big copanies spend lots of time in the dyno rooms to take the guess work out for you because it is such an importnt decesion. JIM

[MikeB]

Originally Posted by bossermj

May want to consider just selling that motor...and buy a 350 instead.

Gave away my 307 back in 1993. Sometimes I wish I had it back!

Nothing wrong with a 307 unless you plan to haul heavy loads up mountain roads. Certainly better than a 305, IMO.

Originally Posted by hugger6933

just don't get to big! the truck will be a lot more fun to drive if the cam is chosen wisely. Also remember when someone says I run bla bla bla that is probably in a 350 and those can take more cam than your 307. JIM

Well said!

[llowlife]

Follow the advise given and you will be fine. I will add my 2 cents however. The 307 is a fine motor, just remember it will never be a "powerhouse". So don't try to make it so. I would certainly give some thought to pulling the heads and replacing the guides and Valve job. I know it will increase the costs and such but these motors are notorious for loose valve guides. Just a thought....Another consideration you may consider is the stock cam you have and add 1.6 rockers. Save you some money... Or a near stock aftermarket cam with 1.6's .....I personally like the Q Jet carb...for mileage and performance. Cheap and plentiful....Just watch for bolt patterns on manifolds. The performer is a nice manifold ...accepts the QJ carb...and are plentiful used....Try to get the newest used one possible if you went that route as there are running changes to the design. You can't give them away so the cost again is nice. Hmmm looks like pulling those heads might be doable after all....These are not necessarily recommendations just different ideas to look at. I would personally rather have a fresh valve job/guides with a stock cam and 1.6 rockers that aftermarket goodies and worn heads. The most important thing is to keep it small and balanced...by balanced I mean parts compatibility.

[Kidd-7]

Thanks for the input; I am planning on having a valve job done, been burning oil this summer. I found a cast iron intake off an 80's Chevy and will be having that machined also, probably will forgo the cam right now. Any ideas on a carb for that intake? Also, anyone know of a good book out there to learn about building a Chevy 307?

[llowlife]

There are some things you can do that will increase performance to an extent that require nothing but elbow grease.

How to rebuild your small block chevy- David Vizard

Older book but its still relevant. He takes you through everything you need to know.

Again I like the Quadrajet carb. Some do some don't. It is extremely adjustable if you want to learn how or just rebuild it and go. Top notch mileage and performance when needed. Also the best sounding carb when those secondaries wake up. Look into some 1.6:1 rockers they should wake it up a little without putting too much strain on the valvetrain. Ask 100 different people and you will get 100 different answers with only a handful of the m being wrong. Look at the drag strip. 100 different motor combination's all going the same time. If possible don't overlook any detail on putting it together. The difference between winning and losing can be in the details. As said earlier there are some things that can be done to help performance without costing anything but time. Good luck

[Jacfourteen]

Originally Posted by hugger6933

just don't get to big! the truck will be a lot more fun to drive if the cam is chosen wisely.

X2, most cam recommendations you read on the cam manufactures websites are for 350 like stated above. The larger displacement makes a huge difference in how a cam acts. My Comp Cams xe268 has a duration @.050" of 224/230 and it doesn't like to cruise under 1400 RPM, so if you dropped that in a 307 it prolly wouldn't cruise under 2000 RPM which wouldn't make a very fun street motor. I would say stick with a cam that says something like Idle-5000 RPM, that way you know it is pretty tame.

[screamin_c10]

What a coincidence, I am starting to warm over my little 307 as well.... Don't let the 350 fan boys scare you off...as far as the cam goes I agree that the Summit 1102 is a good step up from stock IF you are keeping the 307 heads. Remember the 307s sported huge 74CC combustion chambers and puny valves... I would ditch them for a set of 305 HOs or better yet a set of Vortecs...then step up to an 1103 214/224 cam

[Kidd-7]

Originally Posted by screamin_c10

What a coincidence, I am starting to warm over my little 307 as well.... Don't let the 350 fan boys scare you off...as far as the cam goes I agree that the Summit 1102 is a good step up from stock IF you are keeping the 307 heads. Remember the 307s sported huge 74CC combustion chambers and puny valves... I would ditch them for a set of 305 HOs or better yet a set of Vortecs...then step up to an 1103 214/224 cam

Are you saying ditch the valves or the heads? Assuming the valves, but you know what happens when you assume....
And what do those cam numbers actually mean?

[treveiger]

Im intersted in this post. I also have a 307 and is starting to burn oil and next spring thinking about taking the heads to a machine shop to get them fixed. Anybody know would it be cheaper getting new heads or just machining the old?
Thanks

[Beat68CST]

Find a set of like 186 heads, they have 64CC chambers which will help ya out, usually 1.94/1.50 valve combo.

Or 305 heads, they have a nice small, 58CC chamber

[Jacfourteen]

Originally Posted by Kidd-7

Are you saying ditch the valves or the heads? Assuming the valves, but you know what happens when you assume....
And what do those cam numbers actually mean?

He is suggesting changing heads. By swapping to a smaller combustion chamber you can up the compression, which helps make a more efficient combustion = more power. I am running about 10:1 compression and I can run 87 octane with no pinging (But I usually run 91 just to be safe).