Junkyard C30 stepside work truck "build"

[TJ's Chevy]

Originally Posted by 66Submarine

Runs fine up high.

All the more reason to think its valves. lol Idle fine....under load fine...but when cruising you get a little misfire....usually valves not seating perfectly. I've seen my fair share of rebuilt engines do that. My 305 V6 does that...under load its smooth and at idle its the same...but cruising along at 2000-2500 rpm there's a little pop here and there.......Valves.

[66Submarine]

Originally Posted by TJ's Chevy

All the more reason to think its valves. lol Idle fine....under load fine...but when cruising you get a little misfire....usually valves not seating perfectly. I've seen my fair share of rebuilt engines do that. My 305 V6 does that...under load its smooth and at idle its the same...but cruising along at 2000-2500 rpm there's a little pop here and there.......Valves.

No valve job was done on the heads, the valves all went back where they came from, seats and valve faces showed good contact, and when I hooked up a vacuum gauge the vacuum at a fast idle was so steady you'd think the needle was painted on. No problems there.

It only runs smooth at idle and WOT. Part throttle light/moderate load is like you left spark plugs out. If you go WOT it picks up and smooths out.

[deejaaa1]

Originally Posted by TJ's Chevy

Sounds like valve train to me.

X2. had it happen on my 81.
also had a 307 in the 70 Chevelle. never missed a beat.
love your build. down to earth work truck. hope to have mine on the road one day.
also like the fender top work stations. white paint looks great.

[66Submarine]

Originally Posted by deejaaa1

X2. had it happen on my 81.
also had a 307 in the 70 Chevelle. never missed a beat.
love your build. down to earth work truck. hope to have mine on the road one day.
also like the fender top work stations. white paint looks great.

Thanks. The tables on top of the fenders are certainly very handy.

[66Submarine]

Originally Posted by hotrod66

No longer looks like I belongs in a horror film I'm kinda sad now.but good job

Now it kind of sounds like it belongs in a horror movie...lol

[deejaaa1]

sounds nice and strong. any hiccups after the "fix"?

[66Submarine]

Originally Posted by deejaaa1

sounds nice and strong. any hiccups after the "fix"?

Hasn't done anything totally insane like that since. The carb needed/needs some tuning, but no crazy stuff.

General update copy/pasted from another thread FWIW:

It's the 307 out of my '68 Impala with 98,000 on it. I took it apart, cleaned it up, honed it, replaced all the bearings, new brass freeze plugs, moly rings, steel shim head gaskets for correct quench distance, double roller timing chain (to replace the BS nylon one with the nylon all shucked off), new oil pump, quickly smoothed the heads up a little with a die grinder (made me feel better?), and used a mild Elgin E860SM GM blueprint HO 305 cam (202/207@.050, 114LSA, .404/.414).

The Holley 600 and Performer RPM intake were already on it when I got the car, and some short GM chrome valve covers I had and a couple cans of Duplicolor DE1607 made it look less hideous. I used a HEI I had with some light advance springs and ended up with 20º inital for 36º total + 14º from an "AR-12" vacuum advance can.

It's just a very mild and inexpensive "build" that runs nice and should last a long time. It makes 16.5" of vacuum at idle and I haven't noticed any detonation on 87 octane.

The exhaust is some old 1.5" truck headers and dual 2.5" pipes (eventual BBC power?) kicked out in front of the rear tires with Summit turbo mufflers. So far no one has said it's too quiet...

It also did this the other day warming up:

Odd cold fast idle lope - YouTube

Apparently the factory carb jetting was way too lean (it hesitated pretty badly and the plugs looked like they were never ran in anything). Swapping the 65's out for some 68's yesterday made it run much better (still need to check what the WOT jetting is like). I also swapped the orange accelerator pump cam and 31 nozzle out for the smaller white cam and a 25 nozzle.

[66Submarine]

Might as well make an update or two. I finally replaced the rear end a while back (well, six months is a while)...and not a mile too soon for my taste...lol. IIRC I moved the new rear end back 1" via another hole in the perches so I didn't have to mess with the driveshaft. The width was fine, no other problems.

[66Submarine]

Also finally wore out the remold 235/85's And got some new ones. Well...more "new" remolds, anyway...

265/75R16 "Claw" from Treadwright. The old ones got slid quite a bit and still went 40,000 miles, so I can't complain much. Used another set of 16x6.5 wheels; wouldn't really want to go any wider, but I think they work fine. I'd still like a wider wheel for better stability, but those aren't free like these were...sometime in the future. Probably should attack the fenders with a hammer a little bit, too. Running around 45PSI now with no load, seems to be good.

[66Submarine]

And I decided I wanted to make some changes to the 307, so I stuck the 350 I put together for my Impala in there yesterday to run it a while. Basic 350 .030 short block with forged flat top pistons, moly rings, Vortec heads, steel shim head gaskets for correct quench distance, $99 Performer RPM copy intake from Competition Products, 214/224@.050 white box cam from Summit (1103). Basically the CT350 350HP/390TQ GM crate circle track engine with another point of compression. Inexpensive combo that should last a long time and run well for a daily driver.

[66Submarine]

Ended up with my wiring stuff all an hour away (oops), so I did some Roadkill engineering and used my pocket knife, tape, cable ties, and some wires I got out of a garbage can to extended the alternator harness using lineman's splices. Unfortunately, it still might be better than any PO wiring I've found...lol

[Deer_hunter_088]

subbed

[66Submarine]

Clip of new 350 running:

You Tube

[66Submarine]

I also forgot that I replaced the seat with another one I had that had already been recovered. Full foam, too. It didn't quite bolt up, but a little time with an angle grinder, my elitist welding setup, some good enough/functional sheet metal stick welding, and there it is.

[Captainfab]

The new 355 looks and sounds good

The new seat looks good too. I will have to say that I have never seen a blue Lincoln welder

[66Submarine]

Thanks, Cap'n.

Must have been someone in the past that wanted a blue one, I guess!

[66Submarine]

Tuning tip. I'm certainly not claiming to have made this up, but it seems many people overlook the idea. Timing tab only goes to 16º BTDC and you want to check total timing without a dial-back light? No need to buy anything, just divide the circumference of the damper by 10 and make a mark on the damper that distance from the original mark (360º/10 obviously=36º). Mark the distance on a piece of paper or masking tape and use that to transfer it to the damper. Want 32º total? Just line the new mark up with the 4º ATDC on the tab. Quick and easy.

[rusty76]

Awesome tip

[66Submarine]

Thanks, it's certainly very useful IMO/IME.

[66Submarine]

Short (and crappy) clip...no tuning yet. Very happy with this engine so far...should be great in the '68 Impala that will be literally 1,000lbs lighter and have a close-ratio trans...

You Tube

[66Submarine]

First post in a while!

Bad ice on the roads this afternoon, real bad. Hit this patch and lost absolutely all steering, just drifted off with the crown of the road. Slid off and hit a tree. Wasn't even wearing my seatbelt, lol. Wasn't hurt, but it was a pretty good hit. I think the frame and driveline is fine, hopefully I'll be able to get it pulled out and drive it back when everything thaws out (with some minor roadside tinkering). Cab is at least kind of messed up, though. Sucks. Just more stuff to fix, I guess.

A cop gave me a ride to somewhere and had to make multiple attempts to get started up the slight hill. Then got sideways and almost crashed like I did three times in about two miles. Real icy!

Bad end to another bad week. Hopefully I won't have too much to fix.

[65truckowner]

Man that is bad. Glad you were not hurt. The truck can be fixed. post some more pic once you get it home.

[RANDY COX]

WOW hate to really see that...Glad you didn't get hurt. Hopefully you can fix it back...

[Palf70Step]

Glad to hear you are OK.

[66Submarine]

Thanks, guys.

Went to survey the damage today...pretty bad. Still started right up, though. Going to get a rollback out and go from there. I at least need to get the bumper off the tire before I can drive it anywhere. Here are some pictures: