engine swap or rebuild advise needed..

[Jerry]

Hi everyone,

I have a 1986 chevy k10 305 v8, 4x4, 4 speed trans and the engine has 76,000 original miles on it. My question is if I put some add on: new cam and rollers, new Intake manifold, new carburetor, new distributer. I don't want to bore anything out just add-on's. would I gain reasonable hp and if so roughly how much?? Or should I drop in a GM crate motor and if so which motor (motor serial#) should I look at, it will be some what a daily driver.  I will be performing all the work myself either rebuild or swap. Looking for input on both options rather than just the typical motor swap.  Thanks in advance for any expertise on this.  Jerry

[zieg85]

If it were me... I would opt to a 350 engine with a RV type cam for low end torque.  I have never had a 305 engine I liked, maybe I just had slugs... My $.02

[rich weyand]

I have this setup, after much screwing around, and like it a lot.  Tons of torque.  Like 375 ft lbs by 3000 rpm!  Drives great.

Stock crate engine: http://www.jegs.com/i/Chevrolet-Performance/809/10067353/10002/-1?parentProductId=752506 $1500
Torquer cam: http://www.jegs.com/i/Comp+Cams/249/12-300-4/10002/-1 $150 (don't need new lifters or springs w/ new engine.)
Air-gap manifold: http://www.jegs.com/i/Edelbrock/350/2601/10002/-1 (you need the stock warm-air setup for this.  if you want to do the "two chrome pie plates" air cleaner thing instead, get the non-airgap version.)
Edelbrock carb: http://www.jegs.com/i/Edelbrock/350/1406/10002/-1 (I have the correct tuning parameters for this carb on this setup for you if you go this way. any carb you get, you better be able to tune it to the setup!)
Headers: http://www.jegs.com/i/Hooker+Headers/520/2453/10002/-1 (there are other choices that work as well.)

[rich weyand]

Forgot the rest of the prices: engine, $1500; cam, $150; manifold, $225; carb, $315 (tuning parts adds about $50 more); headers, $180.

Under $2500 total.  You can spend a lot more money and get a whole lot less torque, but why would you?

Don't forget: for street use, it's not about horsepower.  It's all about torque.

[74 C-10 Shorty]

I have never had a 305 engine I liked, maybe I just had slugs... My $.02

No, 305's are junk torqueless wonders,LOL, I'd just put a big block in it and have parts breaking torque off idle, can you guess what's going in mine...

[Fairlane514]

Find a 1996-1999 Vortec 350 core and rebuild it. You will have a roller cam, vortec heads, you can run a carburetor on it, it will bolt right in with a few exceptions like the flexplate, and possible electric fuel pump.
I bought a complete Vortec core for 350.00.

[Jerry]

Hey rich,

What distributor did you use on your set? and if you don't mind post me those tuning parameters it would be much appreciated.  Thanks

[rich weyand]

Stock HEI distributor for the stock 350.  Not sure of part number.  Someone here will know.

The advice to get a Vortec core (or a working low-mileage Vortec from a salvage yard from somebody who, say, rolled their truck so the engine wasn't affected) and do whatever rebuild is necessary is sound advice as well.  Depends on how much in the guts of the engine you want to do (although lower ends are not tough to do), and whether or not you want to stick with a more stock (date-appropriate) powerplant or not.  You pays your money and you takes your choice.

That having been said, here is my tuning recommendation for Carter AFB/Edelbrock carb on stock 350 with 76 cc heads, performance dual-plane manifold, long-tube headers, and full duals.  Either stock GM cam or Comp torquer marine/rv/truck cam #12-300-4.

secondary metering jets: Edelbrock 1426, 0.095" (stock jet)
primary metering jets: Edelbrock 1425, 0.092"
metering rods: Edelbrock 1460, 0.065" cruise, 0.052" power
step-up springs: 8#

To set up this tune with a stock carburetor, you will need to purchase:
.092 metering jets: http://www.jegs.com/i/Edelbrock/350/1425/10002/-1
.065/.052 metering rods: http://www.jegs.com/i/Edelbrock/350/1460/10002/-1
step-up spring set: http://www.jegs.com/i/Edelbrock/350/1464/10002/-1

So, assuming you tuned the carb as above, and have everything all assembled in the truck, FIRST follow the engine break-in procedure in the instructions that come with the engine.  Once you have the run-in done and have changed out the first load of oil (and use VR1 plus break-in additive for the run-in, then stick with VR1 after that; there will be other opinions, this one's mine), then:

1. Disconnect the vacuum advance line at the carb and plug the hole. Start the engine and set the timing to 16* BTDC.

2. Reconnect the vacuum advance line at the carb. Make sure it is in the lower vacuum port (manifold vacuum), not the upper (ported vacuum).

3. For idle air mixture, this gets you real close without a vacuum gauge. Screw the idle mixture screws all the way in (do not tighten), then back them out 1-1/2 turns. Start the engine and set the idle rpm to 700 rpm or so. Back both screws out 1/8 turn. Did the engine speed up or slow down? If it speeds up, repeat. Keep backing them out 1/8 turn at a time as long as the engine keeps speeding up. The first two to five times it should speed up. When you back them out and the engine slows down, screw them both back in (clockwise) 1/4 turn.

4. Set the idle speed adjustment to 750 rpm.

5. Put the high idle screw up on the cam and adjust the high idle speed to 1200 rpm.

6. As for jetting, that's built in from above, and you should be close. The worst case lean for the cruise circuit is a cold engine, but warm enough to be off the choke, driving a steady 25-30, and you crack the throttle enough to accelerate but not enough to go on the power circuit. Try different amounts of throttle from that steady 25-30. If you can get the engine to stumble here, it's going lean enough for the fire to go out. In that case, switch to .062/.052 rods. The basic idea is to go as lean as you can in the cruise circuit for mileage without going lean enough to get hesitations or stumbles. So the cruise circuit is the sensitive one. The power circuit and secondaries won't give you any trouble at all.

In the winter, the air has less humidity, and is colder, both of which make the engine run leaner. So let's say you put in the .065/.052 rods and everything runs great. You may end up too lean in the winter, and you could then get hesitations and balky throttle response. The solution is to switch to the .062/.052 rods for the winter, then switch back in the spring. Just sayin', so if it runs great now and it starts acting up come the cold weather, you don't wonder what broke. I can swap out the rods in five minutes, so I don't consider this a big deal.

Anyway, there you go. Should be real close for the stated engine configuration.

[Irish_Alley]

heck if you have $2500, 500 more and
for 3k you can get 400hp 400Torque
https://www.yearone.com/Product/1967-87-chevy-gmc-truck/ct350pc1
3.5k
https://www.yearone.com/Product/1967-87-chevy-gmc-truck/at350pc1

and then
Lt del swears by his 383

tuff dawg engines.

http://www.ebay.com/sch/i.html?_odkw=tuffy+dawg+chev&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0&_nkw=tuff+dawg+chev&_sacat=0

I bought my 383 ( www.delbridge.net/install ) from  them a few years back and love it. No core, free shipping.  Bypass ebay, call him directly with whatever specs you want on it like i did... i specified the intake and cam, 4 bolt main, etc..and he shipped it out two days later.  Ask for Darl.  He's in Arizona and shipped it to VA for free.

http://www.ebay.com/sch/i.html?_odkw=tuffy+dawg+chev&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0&_nkw=tuff+dawg+chev&_sacat=0

[rich weyand]

You're forgetting that $550 of the $2500 was for carb, tuning parts and headers, so it's $1000+ more than the stock engine with the torquer cam -- call it $3500 -- but point well taken.  Oh, and you have to run 92 octane gas.  For only 25 ft lbs more torque.

[Irish_Alley]

details small detals lol you still got the point. just curious where you get your tq numbers from what about your hp?
for 3k 440/450 now if you want to save a little buy a used card and rebuild it so for maybe 100 you can have a "rebuilt carb" i know i have 3 or 4 carbs just sitting all are 600cfm or above and i think i only paid 20  for each one been a while cant say for sure rebuild kits are about the same price
http://www.ebay.com/itm/CHEV-350-434HP-CRATE-ENGINE-BY-TUFF-DAWG-ENGINES-/161031019447?pt=Motors_Car_Truck_Parts_Accessories&hash=item257e325bb7&vxp=mtr
they also come with free shipping and that could save between 200-and 600

[rich weyand]

It's not hard to rebuild an Edelbrock/Carter AFB.  I don't know about others.  All the important bits on the Edelbrock that wear out are easily removable -- there aren't any bits that are pressed in or have to be re-machined or whatever.  So rebuilding a used one is certainly one way to save probably a couple hundred bucks.

The hp (275@4000) and torque (380@3000) numbers for the 12-300-4 cam in the setup described above came from a couple of different dyno simulators.  Yeah, yeah, I know.  But these simulators reproduce pretty accurate numbers for some engine setups for which actual measured numbers are available, so they're probably pretty close.

And it sure drives like the torque numbers are right.

[Jerry]

Rich,
With this set up mentioned and a 700r4 with comp cam 12-300-4 I plan to put size 37 in tires..my question is what gears do you recommended for a daily driver?  Thanks

Jerry

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[rich weyand]

With 37s? 

I have 3.43:1 gears and run 31s.  That comes out to about 3.21:1, which is pretty low but I'm to lazy to change the gears. ;-) 

With 37s, you want to go taller.  A 4.56:1 with 37s comes out the same as 3.57:1 on stock 29s, which you can do no problem with a 700R4, because it will be like 2.5:1 in overdrive.  At 60 mph you would be 1750 rpm or so, and at 70 you would be at 2030 rpm or so, which is about right.

How far along are you in your project?  Been almost a year since this thread started.

[Jerry]

Well the project is a complete frame off, I have all parts mentioned in the thread plus lots more. I have both axles fully rebuilding with all new parts and painted with chassis paint..tomorrow the chassis gets painted I'm just at the mercy of the winds..the winter months delayed a lot too...I'm predicting a few more months for completion now that the weather is getting better...and thanks for ALL your help.

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