Recommendations for waking up a 305?

[CrashEd]

The stock 305 in my fullsize 4x4 with 33 inch tall tires would run 69 mph and just under 20 seconds in the 1/4 mile LOL!! my son just had to drag race it one day. He had a little traction problem like way to much. it really did well i think for the wait i have a topper and had probably 500 pounds of tool in the back. There torquie little motors.

Just get a stock 4 bbl intake try and find one with a old Qjet then take it to like autozone or some other big parts place and traid the Qjet core for a reman for like $150 and put that on and it will wake that 305 up preaty good.

[Tx Firefighter]

I like to build a lot of different stuff for very little money. That said, I've had more than a few 305's given to me.

I usually run an Edelbrock Performer cam, Performer intake, and 600 cfm carb. Combine with dual exhaust and an HEI ignition and you'll likely be happy with the results.

That Performer cam is mild in a 350, but in a 305, you'll hear a nice idle sound and it gives noticeable power increase.

The Performer manifold or Weiand Stealth is a goood bet. The Performer RPM is too much for a tame 305 like you have.

Summit brand headers are actually Dynomax units in a generic box. You can see the Dynomax part number stamped into them near the collector. They are dirt cheap too.

An Edlelbrock carb will be set-and-forget reliable. As an alternative, the Carter AFB is the same carb, but no longer sold new, so if you find a used one, snatch it up. A Holley 600 vac secondary will work as well, but I find them to need more attention over their life span than the Edelbrock or Carter carbs do.

These things have worked for me over the last 15 years. Your mileage may vary. Remember though, go conservative in your choices. You'll be much happier and have a nicer performing truck to show for it.

[Myself]

I agree with Tx Firefighter and Stepside454. I don't want to step on toes or sound like a know it all but, apparently some of these people have never built a 305. Performer RPM does NOT work well on a 305, like Stepside454 said the intake plenum volume is too large. Also big cams like 268H and 280 DO NOT work well. I would go XE262 Comp or the Blue Racer with 442/465 lift. Especially in a heavy vehicle you need to build the 305 for torque. Because of the small bore it does not respond to high horsepower upgrades. The grunt is just not there. Also 4x4 cams work well in a 305 build. The 305 HO heads work excellent on a mild 305 in bone stock form. Some pocket porting and intake port matching will help improve higher RPM performance. Absolutely no larger than 650 carb, the little 305 can't take it. Carter and Edelbrock, 625 & 600cfm work great! Add a free flowing exhaust and a decent air filter and you've got yourself a torquey little grocery getter that will see decent fuel mileage as well.

[smitty62]

It's well known that a 350 is much cheaper to rebuild/modify than a 305 plus when you get done with a 305, you've still got a second rate motor. But don't take my word for it, talk to your local machine/engine rebuild shop. If you lack the skill than a crate 350 is the way to go. Use the 305 as a paperweight

[Draggn66]

Originally Posted by smitty62

It's well known that a 350 is much cheaper to rebuild/modify than a 305 plus when you get done with a 305, you've still got a second rate motor. But don't take my word for it, talk to your local machine/engine rebuild shop. If you lack the skill than a crate 350 is the way to go. Use the 305 as a paperweight

I'm not disputing that the 350 is the better motor and would be the better choice.....if you have a choice. Not everyone has the cash to go buy a crate motor or even to buy a rebuildable 350. Some people have a 305 and that's the only option for them so they just want to "pep" it up a bit. Depending on what you're wanting out of the engine the 305 can be a decent daily driver engine with decent gas milage and still turn the wheels when ya need to. Just one mans opinion

[corn]

I had an 82 that had a 305 that ran like a 350. I asked the PO how it ran so hard. He said the stock cam went south & he put a new 350 cam & lifters in it & nothing else. Sure ran good...

[talonted1990]

try this for a little info http://www.goingfaster.com/spo/325_h...chevrolet.html

the last 305 I built had the performer carb, cam and intake on it with headers duals and 4.11 gears ran pretty good for what it was

[Moneypit]

Thanks for all the info guys. I think just to keep it simple I am going to go with the Performer Carb, cam and manifold package. On the JEG's website(probably not going to buy through them but their website is good for getting info) it says the package comes with the electric 600cfm carb. Jeg's website also says that the electric choke carb is tuned for maximum fuel efficiency and the manual choke carb is tuned for performance. Anyone know if there is really that much difference in the tune of the two carbs or how easy it is to change the tune. Thanks all, you've been great.

[Myself]

#1406 is the carb you want.

[tracterman2]

I for one like your idea...you know a good running 305 may not run near as well as a 350....but its a conversation piece if nothing else...people will think it is a 350 and will not believe you got that out of a 305...stuff like that is always fun to me...building cheap...doing things that people don't normally do...going against the grain...however you want to put it. Plus its YOUR engine...not one you bought...everything you do to it you can feel good about and when you feel the difference in the seat of your pants you'll have the gratification of doing a good job..and doing it yourself. I would like to know how it turns out...I have a 307 and am thinking of doing the same kind of stuff your doing...so keep me posted i would love to know how it changes it..I'm not worried about numbers...how does it feel when you drive it...have fun!

[cabinetguy]

I looked at the casting #'s on the heads that I mentioned in a previous post and they are 882 1.94/1.60 valves with the small combustion chambers for the 305HO you should be able to pick a useable set of these up for less than $100. If you dont have 1.94 heads this is a must.

[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.

[Myself]

Originally Posted by cabinetguy

I looked at the casting #'s on the heads that I mentioned in a previous post and they are 882 1.94/1.60 valves with the small combustion chambers for the 305HO you should be able to pick a useable set of these up for less than $100. If you dont have 1.94 heads this is a must.

882 heads are 1:94/1:50 with 76cc chambers for a 350. A good head but not for a 305. The HO heads end in 416 and are 58cc. They come with 1:84/1:50 valves but most rebuilt are upgraded to 1:94/1:60. Also look at the date code. I think the HO casting was only available from 82-86.

[tracterman2]

will those heads fit a 307?? I was wondering about head options on a 307...to get larger valves...they say the cams and heads are the weak point on those engines

[Myself]

As far as I know all standard sbc heads will fit on a 307. The 416 castings are said to have 165int and 59ccexh volume. I almost forgot about the 601 casting 305 head. It was also found on HO 305s. I'm not sure about the runner sizes for it though. I'm running a set of 416 castings on my wife's '68 right now. It is a .040 over 350 with Speed Pro hyper flattops. I have about 15 hours a piece in reworking them though.

[cabinetguy]

Originally Posted by Myself

882 heads are 1:94/1:50 with 76cc chambers for a 350. A good head but not for a 305. The HO heads end in 416 and are 58cc. They come with 1:84/1:50 valves but most rebuilt are upgraded to 1:94/1:60. Also look at the date code. I think the HO casting was only available from 82-86.

I must have looked at the wrong heads,but I do know that 305's need the small combustion chambers. I feel that your data is correct.

[1fast71]

Junk the 305 and go 350 lol jk um... i would go wit a edelbrock intake and holly carb thats what my dad did and it worked pretty good