Recommendations for waking up a 305?

[Moneypit]

I've got a 305 that I would like to get put a little more "pep" in. I already have a decent dual exhaust with headers and 2 1/4" pipe. I do not have the money to put aftermarket heads on(unless someone knows of some good ones for real cheap, lol). So I was wondering if someone could recommend an intake carb and cam setup that might wake up my engine a little. Im not looking for a hot rod out of THIS truck I just want to add a little fun. Thanks. -Moneypit

[regal8r]

do what im planning on doing and slap a TPI setup on it...u can get the complete setup for around 250-300 bux if u look around enough

[Boog]

Need a few basics first. Current configuration, 2 or 4 barrel carb, HEI distributor or points, tranny and rear gear ratio?

[JAKES 68GMC]

Well, way back in 79, my dad had a 79 Silverado 1/2 ton with a 305. He put on a Edelbrock intake and a Holley 450cfm carb, and cut the y pipe and put on dual glasspacks. He still brags to this day that was the smartest, best running truck he has ever owned. "Spin, wouldn't she spin. If you just touched the throttle, she was right there". He says the same thing over and over.

He just had the stock cam in it, too. Hope this helps you out.

[JAKES 68GMC]

BTW, he also got 16mpg average turning 50 series tires on back.

[2nd_wnd]

I'd spend about $700 and find and rebuild me a decent 350.

It can be done slowly and expense can be spread out over a few months.
Unless you re keeping it simply for fuel economy then mabye the tpi would be better suited

[oldno7]

I would put a 4.11 rear gear in your truck. This will wake up your 305 and make your truck fun to drive. Mine's pretty simple 4-barrel, aluminum intake, headers, and the gears. Run's great! This will not improve your gas milage Have fun, oldno7

[cdowns]

if it's a high mileage engine you're money would last a lot longer by going to a new/rebuilt 350. spending money on a tired 305 will mostly just accelerate the deteriotion of the engine

yyou could get an intake and carb as well asthe updated distributor as they can be switched over to a 350 when the 305goes away but cam lifters and valve springs are usually trash in a blown engine so any money there would be for a very short term investment only

[Moneypit]

The truck has already been down one week and because of my parents car going down the only other mode of transportation I have is my bike. I would like for the truck to be down no longer than another 3 weeks and I already know that this engine is good and NEEDS nothing to run once the heads get back from the machine shop. I am just looking to give this engine a little more pep. I do have a 350 in my 71 GMC but I don't know what condition it is in. I paid $100 for the truck and originally just planned to strip the power steering, and power disc brakes for my 68 but then realized the truck was in too good of condition to be parted out.

As for my current setup I just have the stock 3spd trans and 3.27:1(I think that's right) rearend and 2 barrel carb. I was looking around and thinking maybe the Edelbrock Performer package. I think the Performer RPM package would be a little much without putting new heads as well. Thanks for all the advice so far, please keep it coming.

[Texasdeere]

I wouldn't spend the bank fixin up a 305. To wake up what you have just put a 4 barrel and stock style or performer manifold on it and dual it out. This should "wake up" what you have considerably and shouldn't cost much. Better to save your money and invest in a 350 to "hop up" you will get much more bang for your buck.

[cabinetguy]

305 engines are not that bad.If you get bolt-ons you can always build a 406 later.I had a 62 shorty with a 3.73 posi and a 700r4 tranny,headers and an Edelbrock performer RPM manifold,Edelbrock 625cfm carb and the only internal thing I did with the 305 was put in a Comp.Cam 280h(actually a regrind) That truck would light em up and sounded good for minimal dollars.

[cabinetguy]

Oh and do not get a 350. Find a 400 sbc and bore it out to 406. I just sold a good core for $200 to a friend. you find these mainly in mid to late 70's GMC 4x4 trucks. Dollar for dollar the 406 is king

[Draggn66]

Well anytime someone asks what to do to make a 305 perform better most people say take it out and put in a 350. That may be a good idea since you can't argue with cubic inchs, but sometimes that is just not an option. So here's an opinion to your orginal question.....305's respond very well to mild grind cams like the Melling MTC-1. Intake options are limited to a dual plane intake to keep the only thing the small bore engine has going for it, that being torque. I'd leave the heads on the engine and just do a cam and intake swap. Stab a MTC-1 in it and slap a Performer RPM on top and it will do nicely.

[Moneypit]

The 71 GMC I have is going to be my hot rod. This truck is just my daily driver and has a good running 305 with a fairly fresh bottom end in it. I guess I just worded my original question wrongly. I am looking for a recommendation for a manifold 4 barrel carb and a cam that won't cost a lot of money and will work without having to do anything else other than upgrade the distributor. Thanks.

[71chevytruckguy]

im do the same thing that's done to mine. put a comp 286h cam in it with an edelbroke performer or rpm intake dependin one where you spend ur time, get a good 600 cfm carb, and hei and you'll be set. that's the set up in got in my '69 and it runs real good for what it is. always get complents on the sound and everybody thinks in a 350. chris.

[Joeypilot]

Find a 350.

[jkaylor68gmc]

I spoke with Bill Mitchell a few months ago and he said the major problem with these engines are the headsthat they are pretty much junk. I have one in my '47 and had to build the crap out of it. It does however get my little truck up to about 125mph (swear no lie, have witnesses with a 700R4). I would recommend head work and a change of heads.

[cabinetguy]

The head casting # evades me but they come on the 84 z-28 for a 305.you can pick these up cheap and work well.

[stepside454]

Like has said before, $ for $ cubic inches is the cheapest power, However, its not that hard to make a 305 perform nicely. best thing to do is stay conservative as they are easily over carbed & over cammed.
I had a 86 GMC Caballero (same as El Camino) with a mild 305 that I built that ran 13.80s with 3.23 gears. I used a comp cams extreme energy 262 ( I hope thats right, this was about 6 years ago). KB143 pistons , these gave me just shy of 10.0:1 compression with Corvette L-98 aluminum heads. A performer intake, 570 Holley, DUI ignition, Dynomax headers, 2 1/4" dual exhaust with Dynomax super Turbos.A T-350 tranny with a 2200 RPM con erter.
It ran great, but was also very sensetive to timing & carb adjustments, also got crap for MPG. But, it pulled 16" of vacum at idle & would pass IM240 smog without a problem. John

[Myself]

I agree head #14014416, Crane Blue Racer cam and lifters with 442/465 lift, Weind action plus intake and a 600-650 cfm carb. I'm running this exact setup on my 3850# S10 Blazer with Hei, headers, dual exhaust, 700R4, and 3:42 open rear. This propels me to 14.9 @ 93mph in the 1/4! Absolutely nothing wrong with a 305, you just can't build it like a 350. 305's respond differently to upgrades and you have to build for a 305. Huge cams and open plenum intakes don't work.

[Moneypit]

OK maybe a bit more specific

350= not an option right now for this truck

Cam= Crane Blue Racer cam, comp cams extreme energy 262, comp 286h, Melling MTC-1

Intake= Edelbrock Performer OR Performer RPM

Carb= 600cfm, most likely Edelbrock because less tuning is required than a Holley and this trucks main job is to get me to work

What about the Edelbrock Performer or Performer RPM packages? Are they any good. Thanks alot guys I really appreciate all the help given so far, not only on this subject but others I have asked in the past.

[cabinetguy]

Originally Posted by Moneypit

OK maybe a bit more specific

350= not an option right now for this truck

Cam= Crane Blue Racer cam, comp cams extreme energy 262, comp 286h, Melling MTC-1

Intake= Edelbrock Performer OR Performer RPM

Carb= 600cfm, most likely Edelbrock because less tuning is required than a Holley and this trucks main job is to get me to work

What about the Edelbrock Performer or Performer RPM packages? Are they any good. Thanks alot guys I really appreciate all the help given so far, not only on this subject but others I have asked in the past.

I have used the CompCams in the past and have been satisfied. But I also feel that the 280h cam that I refered to might be one step bigger than your after.And you can save some money by going through a local regrinder. We have a place called Delta camshaft around here and a set of cam and lifters is right around $100.I also feel the 600-625 Carters are a no brainer.Just keep in mind that your manifolds have slightly different rpm ranges and your cam should match.and remember Gears Gears Gears.

[stepside454]

I would use the Performer...not the Performer RPM, The RPM has way to much Plenum volume for this application.
As far as The Edelbrock cams...the Performer is a baby RV cam in a 350, but a solid performance cam in a 305. Dont even consider the Performer RPM cam
As far as carburaters, if your going to stay within 5500 RPMs with it, use a 500 CFM carb...or a Q-jet. the small primarys on a q-jet make it a perfect match.

[mnunn454]

Originally Posted by Moneypit

OK maybe a bit more specific

350= not an option right now for this truck

Cam= Crane Blue Racer cam, comp cams extreme energy 262, comp 286h, Melling MTC-1

Intake= Edelbrock Performer OR Performer RPM

Carb= 600cfm, most likely Edelbrock because less tuning is required than a Holley and this trucks main job is to get me to work

What about the Edelbrock Performer or Performer RPM packages? Are they any good. Thanks alot guys I really appreciate all the help given so far, not only on this subject but others I have asked in the past.

600 CFM Edelbrock is enough for almost any 305.
Performer manifold is fine. Your 305's heads will run out of breath long before the "RPM"'s advantage will be worthwhile

I prefer Comp's cams because of their reputation, plus I 'm running two and am not disappointed with either. "If" you were going with new heads too then I'd get the total "RPM" shooting match from Edelbrock. Call Comp and see what they recommend for your engine and performance goals.

One thing you haven't mentioned is torque converter (if you have an automatic). Save a few hundred more for a higher stall converter. It'll make a big difference for the $ it costs, but be sure to mention it to Comp when you call.

Final thing is if you already have HEI, add an MSD (or similar) box. If you don't have HEI, get it.

Fuel injection would be nice, and really improves driveability, but is (IMO, pls don't flame me) usually not worth the conversion cost or headaches it causes.

JMO.

[KFreddy]

Hi,

I had a 84 'Z28HO back in the day, kinda heavy 3600lbs ran a 15.50 in the 1/4 bone stock. I removed the catalyst and put a bottle of B&M trick shift in the 700r tranny and the Z ran 14.90s all day. now a days I think that the 305s get way too little credit only because there are so many other options out there, for the same cost.

That being said and to answer your questions, I'll start with a question:
Heads- You mention that your getting some head work done to it? If your not too deep into that process think about rebuilding those LG4 or HO heads by replacing the 1.84-inch stock valves with larger 1.94-inch valves, but keep the stock 1.50-inch exhaust valve size, a basic but "good' valve job, including gasket-matching the heads and doing a little bowl work before installing high-performance springs, retainers, locks, screw-in studs, and pushrod guideplates.

Camshaft- COMP Cams XE268H, hydraulic flat tappet with 224/230-degrees duration @ 0.050-inch, and 0.477/0.480-inch lift, on a 110 degree lobe separation.

Intake- Edelbrock's Performer RPM, a no brainer, but check your hood clearence anyway...

Carb- Holley model 0-4776 600 cfm double-pumper carb.

Ignition- ACCEL HEI distributor with conventional mechanical and vacuum advance, along with an in-cap, high-intensity coil.

With the correct exhaust, don't get to big, and a bit of fine tuning I bet you make 325hp and a bit more on the TQ #s and that is a very friendly street motor...

On the other hand a basic 350HO Crate Engine for about $1,800 gives you 290 horsepower @ 5100 RPM, and 326 lb-ft. of torque @ 3750 RPM on 87 octane fuel. Here's the link: http://www.crateenginedepot.com/stor...9-P824C53.aspx