305 Chevy....performance parts?

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Is the 305 the "armpit" engine of GM, or can something actually be done to it to boost its power, BESIDEs putting a 350 or big block in its place? (LOL)
 
Due to the reduced bore size, the choice of aftermarket heads is incredibly limited. I don't think it gets much "better" than the GM Vortec heads IIRC.
 
Well, normally people do just replace 305's with 350's but all is not lost. There are simple old school mods you can do that will wake that engine up. Simple things like a cam, ported intake with a decent 4bbl like a Holly or such, headers & dual exhaust or even an after market fuel injection system.

You're better off than the poor guy with the 307..
 
The 305 responds to modifications better than it is often given credit for. Its smaller bore puts a limit on its HP pontential but for mild street performance its not that much of an issue. The key to performance is the cylinder heads and the 305 didn't get much support. The 305 has the potential to make over 300 HP streetable with bolt ons, a cam change and decent cylinder head with a performance valve job.
 
I had a 307 in a 72 Chevelle. Yeah.....that was just silly.
I know exhaust plays a big role in power because a guy replaced the exhaust on my 82 Mustang 4CYL once, and FAILED to put the catalytic converter on it. Just pipes and muffler. And that thing would scoot after that. That was great! But illegal. I just kinda want to do things under the hood, no engine pulling...
 
OKay lets say I go buy one of those Edelbrock carbs from AutoZone, and want to bolt it on. Would I use the same fuel delivery system? Or are we talking total fuel pump/line remival replacement?
 
Headers will make a lot more difference than the carb. Changing gear ratios works wonders too.
 
If you're going to put a carb (& I assume an intake) on it, you'll need a mild cam & lifters, and at least a less restrictive exhaust (cat & straight pipe or aftermarket cats & pipes/duals). The 305 is capable of modest power, but any decent 350 would be a better choice.
 
Nothing wrong with the 305 but it isn't the best engine to increase the HP on. Gas prices are on the rise by the way!
 
Originally Posted By: lifeson2112
OKay lets say I go buy one of those Edelbrock carbs from AutoZone, and want to bolt it on.


That's just throwing away money. As posted above, it will take more than one magical part to increase performance.

Not trying to be a [censored], but dealing with engine performance is like dealing with a chain. You are only as good as your weakest link. No matter how much you throw at an engine (parts/time/money) you are always limited by the weakest link, be it exhaust, induction, ignition, parts quality etc.

The goal is to set a TOTAL budget, an overall plan, and address the weakest links first. On almost any first gen smallblock, exhaust and cam are the primary weaknesses. You can throw a nice/higher CFM carb on there, but with a restrictive exhaust, and a factory cam (that is often a bit flat in a Chevy), you just wasted a lot of cash on a carb.

Put money into performance that can be "carried over". Frankly, spending money on any internal parts for a 305 is a losing battle in the performance war (especially heads). Money spent on exhaust, and to a certain extent, induction, can be carried over. If you are serious, time to upgrade to a 350 at least (or any 4"+ bore)so you can use big valve heads.
 
Also see if your existing cam is good. I believe the 305 was known for wiping a cam lobe. I know it happened to the one I had.
 
So what your saying is I need to think about parts that I can take with me, when the 305 dies one day....right? Carried over? Stuff I can unbolt and walk away with and put on my next engine.
 
all the cams that work in the 350, work in the 305, and the valvetrains as well.

you can run 194/150 heads (world products makes a 305 head if you dont want the L34)

I pulled 306 hp out of a 305 in my boat with only minor headwork and off the shelf bolt ons.

keep in mind the 305 is not the 307. the 307 block, while a slightly larger bore, never had any of the modern modifications done to it and has a low nickel content - does not wear well.
 
Originally Posted By: lifeson2112
92 Chevy shortbed.


Your best course of action:

1. Find some nice Vortec heads for it, preferably ones that have been cleaned up, maybe had some bowl and port work done to them. Make sure they have good valve springs on them. OE heads are typically pretty cheap.

2. IIRC, '92 should be roller. If not, convert it with link-bar lifters. Comp XE or Magnum series roller cam, the XR264HR looks nice and mild, but much livelier than stock.

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=186&sb=2

3. Is the truck carb'd or TBI right now? The TBI can be upgraded if you don't want to convert to carb.

4. Intake. Edelbrock makes a nice selection of upgraded intakes and one even if you choose to keep the TBI:

http://www.edelbrock.com/automotive_new/mc/manifolds/chevy/performer-tbi.shtml

5. Long-tubes.


I'm probably missing something, but these parts are ALL swappable onto a 350 if you choose to go that route later.
 
Armpit engines, lol. There's a reason the 305, 262 and 267 are armpit engines, If you find the right deals you can replace the 305 with a 350 for less money than modding the 305 to make the same power as a 350. Other than to be different, why bother with the 305?
 
Originally Posted By: ms21043
Armpit engines, lol. There's a reason the 305, 262 and 267 are armpit engines, If you find the right deals you can replace the 305 with a 350 for less money than modding the 305 to make the same power as a 350. Other than to be different, why bother with the 305?


cuz sometimes its what you got. A factory new 260hp 350 is about $1500-$1600 from GM. You can get a factory 305 there or more for less. A lot less. As I said, I got a dyno verified 306hp for about $400 and my time.
 
I had a 305 in a Malibu.
Low compression and soft cams really hurt.
If you want power , a decent cam is a must. but without upping the compression, you won't get a lot out of it.
A thinner head gasket won't cut it - you need to shave the heads or get new ones.

That link given by mechanicx ^^is a very good start.
 
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