how to gain power?

[my 85 gmc]

Please help me out guys:

My truck is an 85 GMC Sierra Classic all original and has a LE9 305 engine with 50,000 miles. My question what part should I add to truck first to gain some power and low end torque a intake, cam(which cam is best suited) or headers(which brand)?

Thanks Rob

The trucks only current mods are dual exhaust and x-pipe.

[Russell]

I personally am planning on buying hooker headers. A performer intake and carburator will do lots for you as far as power is concerned. Probally your best bet is to drop a 350 in though...

[1FaastC10]

350 is by far the best mod you can make to your truck. the 350s 4" bore will unshroud the valves considerably and create more air flow. installing a 350 will make future upgrades have more of an effect on performance as well.

[my 85 gmc]

I plan to replace the 305 with a 350 in a couple of years once it gets a few more miles on it but I'am just looking for a little more grunt for now. Any suggestions?

Thanks Rob

[1FaastC10]

do stuff you can transfer to the 350. intake and carb would be a good choice, and ignition. it sounds like you've already got a good exhaust system. you may even notice some improvements from cooling system upgrades like a good water pump, 4 core radiator, electric fans, etc. dont waste your money on anything below the heads in a 305.

[zzChevy]

First thing I'd do is do some reading. You might find specifics on your particualr setup.


I did read an artical a while back.....let me get it.........ahhh..here it is.......in Chevy High Performace Mag. about a '79 Malibu wagon that had a 305 in it with 110,000 miles. It ran a 20.2 at 69 MPH in the quarter at stock and with 2.41 gears out the back. After a few bolt-ons (RPM Performer intake, Demon Carb 525-cfm, Ram-Air Box, Heddman Torque Step Headers, Dual Exhaust with Hedmans free flowing cat converters, X-Pipe and Turbo Mufflers) they dropped time to 17.5 at 77MPH.

They even added a 175 pound shot which got them to 16.1 at 83 MPH.


Just an FYI...

[stepside454]

MY85, Edelbrock Performer cam & lifter set is a great improvement. The performer or performer EPS would be a big improvement to. as far as carb, keep the Qjet if it works good.
just about any Brand header is decent depending on how much you plan to spen, stay small tube & pay extra for the ceramic coat.
350s of course make more power per $ than a 305, but 305s can perform well with the right combo.
My 76 C10 shortstep ran mid 14s with a mild 305.

[1972C10]

Originally posted by zzChevy
First thing I'd do is do some reading. You might find specifics on your particualr setup.


I did read an artical a while back.....let me get it.........ahhh..here it is.......in Chevy High Performace Mag. about a '79 Malibu wagon that had a 305 in it with 110,000 miles. It ran a 20.2 at 69 MPH in the quarter at stock and with 2.41 gears out the back. After a few bolt-ons (RPM Performer intake, Demon Carb 525-cfm, Ram-Air Box, Heddman Torque Step Headers, Dual Exhaust with Hedmans free flowing cat converters, X-Pipe and Turbo Mufflers) they dropped time to 17.5 at 77MPH.

They even added a 175 pound shot which got them to 16.1 at 83 MPH.


Just an FYI...

Man beat me to it i was about to tell him about that

"Project Three Oh Why"

I read that same article they tryed to make the point that all of them upgrades would transfer over to a 350 but they used a tiny carb I dont think it would transfer over to a 350 that good.

But other than that all worthwhile transferable upgrades.

[chevyfan420]

what about a rearend swap? Intake and carb are good but being an 85 you might still have to go for emission testing. Headers and duels go together like beer and a Leafs game, you can't go wrong with those!! Maybe a hotter coil if you still have money left.

[LOHRTBT]

You need to take the route of the 305 killa Gerardo!!

[8t5Silverado]

16.1 sec @ 83 mph...and that's with nitrous on a 4 bbl V8....how sad.

A turbo would make the largest difference.

Find a decent Mitsubishi turbo in a scrapyard and order some mandrel tubing from Jegs, build your own exhaust, and your good to go.

If an OEM 2.5L turbo four (completely stock with 2 cats) can run 13.2 sec in the 1/4, imagine what a 305 could do....

If you're not that adventurous, I would simply get stuff that can be used on a 350 in the future...

[my 85 gmc]

Thanks for the suggestions guys keep them coming, also I have one of them Ram Air boxes that Chevy High-performance used in the article but have not tried it yet.
Will headers make any difference or are they just going to give it a better sound?

Rob

[chevyfan420]

they'll make a difference in performance and sound

[zzChevy]

Originally posted by 8t5Silverado
16.1 sec @ 83 mph...and that's with nitrous on a 4 bbl V8....how sad.

A turbo would make the largest difference.

Find a decent Mitsubishi turbo in a scrapyard and order some mandrel tubing from Jegs, build your own exhaust, and your good to go.

If an OEM 2.5L turbo four (completely stock with 2 cats) can run 13.2 sec in the 1/4, imagine what a 305 could do....

If you're not that adventurous, I would simply get stuff that can be used on a 350 in the future...

Even though it maybe sad, the block still handled it. Pretty good don't ya think?

[my 85 gmc]

Thanks for the suggestions guys since I can't actually drive the truck until spring thanks to these damn long Canadian winters, I might as well work on improving the truck.

Rob