Crate motor wanting more!

[jason7698]

New to the board and just bought my first old truck a 1971 c10 swb with a new (2500) miles 290hp 4 bolt main 350 crate motor and 350 turbo trans. Now to my questions keep in mind I'm new and green so if the questions seem silly there is a reason. The engine has an edelbrock 600 carb electric choke on an edelbrock performer intake with long horn headers other than that the engine is stock and it does ok but I am wanting a little more out of it (330-350HP or a little more). It is a daily and will never see the strip and I am wanting to keep some decent mpg so nothing to wild. I know the heads and cam need to go but I don't have the funds for a new set of heads and cam only one or the other. I was thinking about keeping these heads for now and getting them pocket ported and some valve work done and putting in a cam maybe a Voodoo (opinions please). Lastly I have read allot about the ramhorns v/s after market headers and now I don't know what to do so let me have all the suggestions and opinions!! This is a great website and I've learned a ton already!! Thanks Big J

[Shyguy]

Welcome to the board from Southeast Missouri.

Have you done a good tuneup on the engine? What is the timing set at? Most people have found if they set the timing in the 10-12 degree range the engine runs better.

I am sure someone else will chime in with more information on how to get the best hp increase with the least amount of money spent.

[au03z71]

Call Comp Cams or Lunati and get yourself a cam. You let them know what you want and they'll hook you up. You will also need to find out if it's a roller or flat tappet cam engine.

[MVHandy]

Cam intake and maybe carb. If you look at the specs on the GMPP crate motors the 290,330 and 350 HP are identical in the bottom end, the difference in the engines is in the cam. If you look at the specs you can get a good idea of what changing cam lift, duration and spacing can do.

Makae sure to get good advice on a cam from the major manufacturers tech lines as you need to match it to the weight of the vehicle, RPM range and such or you'll either blow something up, end up with a dog or have the wrong combination of HP and Torque curve for what you need.

[Schwinn68]

if you want a different carb, I'll trade you a edelbrock 750 manual choke for your 600. I would change the cam to get the bump in power you're looking for.

[68Stepbed]

http://www.classictrucks.com/tech/08...rts/index.html

Nuff said.

Personally, I would ditch the Edleburp carb and get a Holley for better overall performance.

[vasquezmrysvll]

simply changing your heads and intake with 062 vortecs and matching intake will get you into the 330-350 range, and a decent cam and your on your way!

[Wrenchbender Ret]

The 290 HP engine has quite a bit of cam already. I think if you get more with the auto trans. you are going to hurt driveability & gas mileage. I would look into better hads like Vas Q sugested.

[junkyardjohn]

YOUR MOST OF THE WAY THERE , WITH AN INTAKE, CARB, & A SET OF HEADERS. I PERSONALLY LIKE EDELBROCK CARB.S & WOULDN'T TRADE ONE FOR THREE HOLLYS. (JUST PERSONAL PREFERANCE.. SOME PEOPLE LIKE DODGE PICKUPS FOR CRYING OUT LOUD. ) I ALSO LIKE LUNATI CAMS A WHOLE LOT BETTER THAN COMP. CAMS & THEY OFFER A VOODOO SERIES KIT (WITH LIFTERS) IN A LOW RPM DUAL PATTERN .468-.454 LIFT THAT HAS GREAT STREET MANNERS. DON'T GO CRAZY PORTING & GASKET MATCHING YOUR HEADS. THEY'RE PROBABLY FINE JUST LIKE THEY ARE. I'VE SEEN A WHOLE LOT OF PEOPLE RUIN A DECENT SET OF HEADS OR AN INTAKE MANIFOLD WITH A DIE GRINDER, BY NOT KNOWING WHAT THEY WERE DOING. IF YOU WOULD LIKE TO POLISH UP THE RUNNERS ON BOTH.. THAT O-K, BUT REMEMBER.. YOU'RE TRYING TO REMOVE AS LITTLE STOCK AS POSSIBLE. YOU JUST WANT TO SAND OUT THE ROUGH CASTING PORES, TO MAKE THE AIR-FUEL MIXTURE (& THE SPENT GASSES) FLOW AS SMOOTHLY & EFFORTLESSLY AS POSSIBLE. (IT'S FREE.. JUST YOU'RE LABOR & A FEW LITTLE DRUM SANDING DISCS FOR YOUR DREMEL TOOL) JUST THOSE TWO THINGS WILL PROBABLY FREE UP ABOUT 15 PONIES. I THINK WHAT YOU MEAN IS LONG TUBE HEADERS, & THEY WORK GREAT. WHERE MOST PEOPLE HAVE COMPLAINTS ABOUT THEM IS HANGING DOWN LOW ON A LOWERED TRUCK.A 600 CFM CARB. IS PLENTY BIG ENOUGH FOR YOU APPLICATION. HOPE THIS HELPS & WELCOME FROM S/E KY JOHN

[jason7698]

Thanks guys for all the responses one other thing in my first post I meant to say ramhorn exaust sorry lastly my truck is lowered 4 inches so will this effect my header selection and should I go with after markett headers over the ramhorns?

[storm9c1]

Originally Posted by jason7698

Thanks guys for all the responses one other thing in my first post I meant to say ramhorn exaust sorry lastly my truck is lowered 4 inches so will this effect my header selection and should I go with after markett headers over the ramhorns?

This discussion seems to come up over and over. I myself is struggling with the same decision. Seems like the consensus is that long tube headers (or very nice tri-ys) are the way to go. But you may run into fitment problems with both, esp on a lowered truck. Anything else like block huggers or cheapo headers and you are better off with the ramhorns.

[68Stepbed]

I'm running long tubes with a 3.5/5 drop. I've bottomed out twice in 3 years. Those two times were on those rediculously big speed bumps that I went over too fast. I don't think you will have any issues with long tubes.




You can, however, look into the Sanderson shorties from ECE.

[POPO1984]

What headers do you run

Originally Posted by 68Stepbed

I'm running long tubes with a 3.5/5 drop. I've bottomed out twice in 3 years. Those two times were on those rediculously big speed bumps that I went over too fast. I don't think you will have any issues with long tubes.




You can, however, look into the Sanderson shorties from ECE.

[FLDBRED]

The Vortec heads will give you 30-40 HP,that's hard to beat for the price!

[68Stepbed]

Hedman Elites. I don't remember the part #

[jason7698]

Ok if I go the Vortec route should I look for some used ones or should I buy new what brands should I look at remember I'm on a budget so help me out!!!

[red69ss]

if your on a budget I would suggest tuning the current setup as suggested above you'll be suprised what a difference timing makes, I run about 30 degrees total timing on my 350 with what I estimated at 300 hp and it was very stout and throttle responsive. I had a crane cam with about .450 lift in it and it needed a stall converter something else to consider when choosing a cam, which is what I would do if tuning didn't work you can buy a cam kit cheap, where heads are a little high in price. what rearend gear do you have? this will deffinently effect the way the truck feels performance wise. but if your driving it daily you don't want to go overboard engine or rearend wise or it will get terrible gas mileage...... the beauty of these gm crate motors is they should be reliable if you start making a lot of mods to it you will likely lose that .

[junkyardjohn]

YES.. TO TAKE ADVANTAGE OF WHAT YOU ALREADY HAVE, YOU'LL NEED HEADERS. I LIKE, & HAVE USED (ALOT OVER THE LAST 25 YEARS) DOUG THORLY TRI-Ys OR HOOKER COMP.S OR SUPER COMP.S IN THESE OLD TRUCKS FOR BOTH BIG & SMALL BLOCKS. NO FITMENT OR DRAGGING ISSUES. THEY'RE A LITTLE MORE THAN THE CHEAP ONES, BUT BELIEVE ME, YOU'LL BE HAPPY WITH THEM. AS FAR AS NEEDING A STALL SPEED WITH A .450 LIFT CAM?? NO. AS LONG AS YOU'RE RUNNING ANY REAREND GEAR FROM 308-1 TO 456-1 & LESS THAN A 32" TALL TIRE, A STOCK TORQUE CONVERTER WILL WORK JUST FINE.YOU WON;T NEED A STALL CONV. AT LESS THAN ABOUT .525 LIFT. WHEN IN DOUBT CALL ANY REPUTABLE CAM TECH. LINE. (BESIDES COMP. CAMS,... I NEVER HAD ANY LUCK MAKING ANY SENSE OUT OF THOSE PEOPLE) KEEP IT SIMPLE & LEARN AS YOU GO. JOHN

[jason7698]

Thanks for all the info and suggestions I will keep you guys posted and get some pics of my new/old bucket up!!

[Bad70sbchevy]

Just throwing this out there, but what about bumping up compression with some pistons?This boosts power and a little fuel efficiency at the same time. Changing the cam can wake your engine up, just don't go over 300 duration as a rule of thumb if you intend it to be a daily driver. Look for somethin that matches your combo, best thing to do like someone else said is to call the cam company to help you out, personally I like Comp Cams myself (got a 292 on my 355). Only thing though this will kill your gas mileage if you get a too radical cam. You might be able to squeeze a couple horsepower by running a larger air filter ( the bigger the better). Same thing with changin carbs to a double pumper, you'll get more power but it'll cost you in gas mileage.

[Tink]

I'd say it all depends on your budget... once you know what kind of $ you have to play with you can choose the mods that give you the most bang for the buck. If you don't have a lot of money, switching to flat-top pistons is out of the question most likely as it will involve a total removal and tear down as well as finding someone to press the pistons on/off the rods.

I'd say headers and free-flowing exhaust... do you know the compression ratio of the motor in order to choose a good cam for your set-up?

[jason7698]

Everything online has said the comp. ratio is 8.5:1 but I have read that some are even lower?

[68Stepbed]

As it's been stated already, the 290HP cam is pretty stout to start with. It just has a wider lobe speration angle(LSA) to smooth out the idle. If you read about these engines, they're rated at 290hp-326ft/lbs tq with an Edelbrock Performer intake, 600cfm Edelbrock carb, and open headers with 1 5/8" primary tubes. The article I linked above states that with only changing to a 650 Holley, it made 323HP-347ft/lbs tq.

My suggestion is a 570 Street Avenger carb, a good set of headers and exhaust, a good ignition system, a set of aluminum pulleys and an electric fan conversion. All of this should cost about the same as a set of heads, but will maximize the parts you already have. You can always change heads later as budget allows and will be much more extreme with these parts. Even if you just change heads now with everything else you have, you actualy wont gain much more power because your exhaust and ignition will choke the heads back down.

Heads will make a big change, if everything externally is setup to work with them. Change your external parts first to maximize what you already have.

[junkyardjohn]

LETS NOT GET CARRIED AWAY GUYS. THIS FELLER WAS JUST ASKING ABOUT CHEAP.. FAST.. HORSEPOWER HE COULD BOLT ON WITHOUT A WHOLE LOT OF EXPERIANCE. NOTHING WRONG WITH LEARNING.. WE'VE ALL DONE IT. HE'S GOT A GOOD SOLID BASE TO START WITH. HE WASN'T ASKING WHAT I'D DO TO ONE OF MINE, OR WHAT ANYBODY FIGURED THEY COULD DO TO THEIR'S. LETS TRY TO KEEP IT SIMPLE FOR HIM. JOHN