[Chev307]

Hey guys- I am in the process of rebuilding/building up a 307 i picked up for $100.00 that is complete from oil pan to the carb. I am going to school full time, but have decided that I want to build it up on the side and maybe throw it into a little s10 pickup from the late 80's/90's which I feel would make for a quick little toy to tinker with. I've started tearing it down and running the numbers and have found out that it has 305 heads #354434 and that the motor, due to its overall condition, could use a complete redo. I know that this motor, even after being built up, wont make horsepower that is worth bragging about but I wanted to build a 307 because it was different and the fact that I don't need 400 horses to move a something as small as an s10 pickup, but would still like to make it as aggressive as I can.These are a few of the things I would like some suggestions on from some of you guys out there who know a little more about these topics than I do...

1. Since I am shooting for a fairly aggressive motor, would I be better off finding a cheap set of 350 heads or sticking with these 305 heads since I already have them?

2. I plan on keeping everything in the bottom half of the motor (ie. crank, pistons, rods) after I clean them and install new bearings and hot tank the block. I would like to replace the stock cam with one that is more aggressive. I dont need to turn insanely high RPMs but would like a cam that sounds good and performs good for use not only in town but on the highway. What cam specifications and brand would you guys recommend with the little bit of information that I have given you in this thread?

-Thanks

 

[seven up]

I would say just getting the motor to run well would be an accomplishment. Save your money for your next build. You are only leaving room to change the cam so that limits the results you will get.

 

[DoubleVision]

This is my suggestion on a quick street 307.
If the block can reuse the factory pistons by all means do so as the aftermarket pistons all have .020 off the compression height.
After you get the block back from the machine shop and your ready to assemble, scrub the bores good to make sure no hone grit is impregnated in the cylinder wall. Use a paper towel and WD40, if the towel picks up gray, the cylinder isn`t clean.
Next I would find a set of 416 casting 305 heads. These have the larger 1.84 intake valves and a decent intake port, the small 58cc chamber will get your compression ratio in the mid 9:1 range. I would use a summit cam kit that has the same specs as the edelbrock performer plus cam. Duration @.050 is 204 in. 214 ex. Make sure you get the springs that match the cam.
Use valvoline racing oil to break in the cam and run it from there after to make sure the cam doesn`t go flat. regular motor oil had zinc and other anti wear agents removed so they no longer provide the protection flat tappet cams need.
To compliment the cam I`d use a cloyes double roller timing chain set.
A edelbrock performer intake or eqiv. and a Quadrajet carb. A HEI ignition with a hotter coil, module, brass terminal cap and rotor, spiral core spark plug wires. A K&N air filter to top it off with. A set of small tube headers with a low restriction dual exhaust system. This mild combo will give excellant street performance, fuel economy in a light S10, and won`t break the bank.

 

[Plaintoast]

I have a 307 that I race, and it moves along pretty well, better than any of my competition seems to. Mine is bored .030" or .040" (can't remember), and like other said, 416 (305) heads are good ones. This one I currently have in my race car has 601 casting heads on it though.
For the street, look for duration in 214-216 range, .470ish lift, 108+ LSA.
I like the 601s for the extra compression, but I've done the same build for another racer using the 416s, and run the 416s on another of my own. They both work. 434's are OK, so if you don't want to scrounge up another set, have a good rebuild done on them, z-28 style springs, and call them good.
Look for a small carb, 600 Max. We are allowed to run 4 barrel quad, 2 barrel rochester, or most of us choose to run the holley 4412, 500 CFM 2 barrel, which also wouldn't be a bad choice at all. Plus, it'd be fun to show people they just got beat by a little 307 with a 2 barrel sitting on top!

 

[Chev307]

Thanks for the suggestions. This is just a little project I have going on the side while I am attending college and working part time so it gets what little money and time I have left to spare, but I am looking forward to building it up using these suggestions and seeing how it runs!

 

[ap72]

there's a cam Elgin makes that is great for somethign like this, but it would require you to get compression to mid to high 9's.

its a 274 216 .450" single pattern on a 106LSA. the whiole kit from Competition Products is like $80- great price, durable cam, good sound, good mid range. It is NOT the best cam on the market but it is a good cam at a very good price.

 

[Plaintoast]

Elgin does make some decent cams, definitely good for the price, but 106 on the street is going to make for a really peaky power band, especially in a smaller cube motor like this. Those specs are pretty similar to an isky lift rule cam I use often.

 

[ap72]

Elgin does make some decent cams, definitely good for the price, but 106 on the street is going to make for a really peaky power band, especially in a smaller cube motor like this. Those specs are pretty similar to an isky lift rule cam I use often.

Its not as peaky as you'd think. the durations are relatively low so power falls off fast after about 5500 but like I said it has great mid range- could maybe use a 2000-2500 stall, very mild.

Here's a quick DD I did just to show the curve, as always its probaby off by a few percent, and I assumed he'd use ported 416's with stock valves, a Performer intake, and 9.5:1 compression.

Isky cams are great too, but about twice the cost.

 

[cobalt327]

Now, run a sim using everything as before except 272 214 .460" on a 112 LSA. Then overlay that over the previous graph.

 

[Chev307]

Thanks for the replys and heres where im at now...I did find a set of 416 heads with roller rockers for $100 that i am (hopefully) going to pick up this weekend. Im still looking for an edelbrock intake and a 4 bbl Square bore holley carb but i think i have my cam package picked out. Its from Comp and its the COMP Cams K12-239-3. It comes with everything needed for the heads, ie springs retainers...Do you guys think this would be a decent cam given what heads and stuff i hope to have? I found out on the summit page for the cam it's comps xtreme 4x4 cam, but I plan on putting the engine in a car (possibly a nova) Will this cam work for such an application or would it be better meant for a 4x4 application? The reason I picked this cam is because it was the one used in a Super Chevy Magazine build with their 307, although they decided to go with Edelbrock heads (which i don't have $600 for!)

Heres the page:
http://www.superchevy.com/technical...sucp_0604_chevy_engine_performance/index.html