The Truth About The Small Block Chevy 305

In this video I go over the small block chevy 305 and how it can still be a viable engine if you use it for it's intended purpose.

[maryannmoran-smyth]

As an engine builder, I tore down many a Chevy 350 and 305s and one thing I noticed that the 350s had a lot more cracks between the two center valves and the bores-were closer together creating quite the heat spot… However, on the 305s there’s a healthy distance between the cylinders where the cooling could be more effective, which was a great advantage because of my experience, I rarely saw 305 cracked head or block therefore, depending on how you build the engine, the 305 can handle a lot more more heat and run cooler than the 350… Fact… Keep on rocking

[madcowusa]

My C10 truck's original 305 is now 41 years old, and besides basic (often neglected) maintenance and occasional external bits like fuel pump and valve cover gaskets, it just keeps running despite sitting outside year round next to salt water. It's remarkable to me this thing is still running fine after 41 years. Hauled 60, 000lbs of topsoil and gravel in the bed past summer, one yard at a time. Original 3 speed transmission too. Absolutely blows my mind. She's a keeper.

[SOLDADITO]

A 305 bored .30 over, a healthy cam, good flowing set of heads, TPI (from the 80'), Specific tuner chip for engine build, true dual exhaust, torque converter with a good stall in a 700R4 w/ lockout bypassed, and that little 305 will perform trust me.

[orvalaltwasser]

I bought a 1997 Chevy 1/2 truck, used with 60, 000 kms. I sold it to a farmer buddy, when the clock got 120, 000 kms. It is now showing 570, 000 kms on the original engine . The truck never got any TLC after I sold it. The body is ready to fall off, as it never, ever saw a car wash. The Transylvanian is tired, but the engine still runs pretty damn good ! I’ve owned 3 trucks with 350’s, 1 six cylinder, one 4.8l, and 3 5.3 l engine. All were decent engines, except for the 4.8. It didn’t have enough power to pull itself on a soft, muddy road ! Enjoyed your video!

[omgmyspleen]

Had a 305 in my ‘83 TA. First build on an engine. Machined the block, .030” over flat top Seal Power pistons, World SR torquer heads (170cc runners, 58cc chamber, 1.94 intake and 1.5exhaust) comp XE268 cam, roller 1.6 rockers and Edelbrock performer RPM intake topped with a 600CFM carb. Made 370hp, a lot better than the stock 140.

Was a great little engine and ran like a champ. Currently putting the car together with a Blueprint 400 that made 520hp/tq on their dyno. Gonna be a riot of a car.

[Chevrolicious.]

My understanding was always that, for the price of building a 305, you could just build a 350 instead. I think the 305 is nice if you're building a cruiser, and you can definitely still squeeze some power out of them. I have an all-original 84 Z28 with the H.O. motor, and the main thing that kills power on that engine is the exhaust and emissions systems. I think they made 195 bhp in 84. A little port job on the heads, headers, and decent exhaust starts letting the engine breathe a lot better.

The engine isn't weak, it just has asthma.

[mitchelkane]

I put a 305 in my 84 Camaro with around 300hp. It's fun to drive but the main point is I get 22 mpg on the hwy. Where's the 3:50 I took out with the same power got 17 on the hwy. The only difference is I get better fuel mileage went cruising. Floored it gets about the same as the 350 did

[seancedio]

I can tell you for fact that the L69 305 H.O. made more than 230 h.p stock. On the dyno with the factory Rochester carb, intake and est distributor with timing set to 42 degrees, motor was completely stock from a 84 Z-28 only performance part used was the dyno headers and 18 in collector extension with 3 inch bullet race mufflers. Stock it made 297 h.p. with 345 ft lbs. Then we built the motor to run NHRA super stock, look at the rules, when finished motor made 629 h.p. and 593 ft lbs. Peak h.p. was 7600 rpm and peak torque was 5800 rpm. Car set A national record back in 1988 and held it to this day for its classification. Engine was built at L&L Auto Machine in Groton Connecticut by David LeBrun. Look up the History in the archives. The 305 isn't a bad Engine, people just automatically assume they were junk cause it was gm's entry level V8 for passenger cars and trucks.

[gavincarroll]

Ive actually heard good things about the 305 ho heads like the 416 and 601 i got a set with 1.94 valves im going to put on a 350 hoping for one hell of a runner

[turkeyssr]

Great video. I'm still driving my 1983 Impala with a 305. It was all my grandparents could afford at the time.

[brianmilliard]

Dude,
Back in the 80, s Chevy 307, 267, 305; Ford 302 & Dodge 318 where and still are a fun engine.
They where dirt cheap, big plus.
We use to add a dual plane intake, usually eldelbrock a qaudrajet factory 4 barrel, hand port the intake and exhaust manifolds as well as the heads and maybe put new valve springs in, lol that’s a big maybe. Then do a hill Billy valve job and hand lap them to seat better.
Finish it off add a cat back exhaust system.

[thecreativecontractor]

Always cracked me up when everyone said the 305 was junk. Port the heads, throw a cam in it, gap the rings and put a pro charger on it. That little combo in a 89 Formula with 3:73 gears will shut allot of mouths!!!

[etmesi]

My 79 Olds Cutlass with a 305 was built in Sep 1979 in Arlington TX. For some reason it not only has high revs but pretty good take off power. There is enough power to raise up on the front where there is limited steering traction. There was a recall that 305 cams were known to chip, GM would have replaced that, mine never chipped, so I think the factory used a different cam. In 2019 I finally change the power steering pump. The bracket GM used is from a 1980 Cutlass with 1979 hose lines, I have a special hose made, could not just buy that. The factory hood is fiberglass another strange one. I bought this car from a large company fleet car said to be a COPO.

[wolfaja]

As a man who almost always works on smaller displacement engines I’m pretty confident you could make a 305 come alive. It’s possible for almost any engine to make 600 or 700 horsepower if you throw money at it. In terms of a 305 I wouldn’t bore it out much if at all but if I wanted 400+ I’d definitely put in new bearings and deck it. I’d also use a stroker kit with forged internals and some trick flow 175’s and of course do a new cam, intake manifold and 750cfm carb. While doing all of that convert over to a hydraulic roller setup too. I’m fairly confident if you do that you could make 400+ horsepower with a 305 and depending on the compression you might be able to squeeze 500 out of it. That being said you could build a 350 sbc or swap some junkyard ls into it and do less mods, spend less money, and gain more power. In my opinion the only reason to keep a 305 is if you want to maintain the original engine in a classic car. The other thing people don’t really talk about is the fact certain year model 305’s can only bolt on a few different transmissions. For example the 85 and older 305 can really only bolt on a t5 and whatever the automatic transmission that came out those years. You could in theory bolt a t56 to it with an adapter but for just straight up bolt one that’s really all you can do. The t5 has got to be one of the worst manual transmissions known to mankind. The case flexes and causes gears to climb each other and seals to break and over all the transmission to grenade itself. That’s the real drawl back of the 305, if you manage to get it to make decent power you still have to do something with the transmission because it can only hold about 300 ftlbs before you risk destroying it which would cost another 1.5-2k. There’s no way to strengthen the t5 gears for GM’s either because there’s not an upgrade internal kit for it. The only way would be to use the kits that are for fords and then run a type of hybrid spline since ford and GM splines have a different tooth count. The 305 was doomed by GM from the get go and gen three t/a’s and Camaros have got to have the worst power train ever put in a muscle car.

[vitodelorto]

Man, I have an 84 El Camino Super Slow. It has 60k origional miles. It's a beautiful car. I don't want to thow away a fantastic running, low mileage engine, just because it's not a 350. So far, I have put a Holley 450 on it. That made the biggest improvement, over the 600 Edlebrock. I advanced my total timing a lot. Deleted a spring, and added weight to the centrifugal weights. Added an underive crank pully. It runs fucking sweet. Burns rubber all day, and pulls real hard. I have a lot to do to it yet. I am extremely pleased with it right now. There is a lot you can do to those engines, without spending much, or going in. Whenever I wear this engine out, I will upgrade. If I never wear it out, Im good with that too. The car is fun as hell, right now. Man, when it showed up at my house, it ran great, but was a LEAD SLED. not anymore😂
So don't be down about that 305 you got!

[cuzz]

I had a 305 in my 78 Olds Starfire..Old version of a Monza. In a small light car it was decent and I added an aluminum intake and 4 barrel and it was fun as hell to drive. Later I got an 84 Z-28 and the 305 4 barrel was dismal, I swapped it to a 350 TPI.

[danwohlslagel]

I had an '83 Z28 back in the day with a 5.0 HO ( 305 High output). It had the T5 5 speed manual with a 3.73 posi trac and I could easily keep up with the 5.7 L TPI IROC Camaros -- which were among the quickest for the era.

[ACamaroGuy]

I had an 84 Z28 H.O.
.060 over bore, port/polished Vortec heads with undercut swirl tipped valves, headers, cammed, 76 vacuum distributor, bypassing the OBD 1 computer, Edelbrock RPM intake, Edelbrock 1405 carb... I ran 13.4 in the quarter. I miss that car. It was so much fun.

[Muleskinner]

I’ve got an 80 k10 on 35’s with a sm465, np205, and 3.73 gears with a 90 model 305 in it. I’ve got a 500 cfm summit carb on a performer intake, long tube headers, and a recurved distributor (all in at 2500 rpm). Ton of power no, but towed 3 round bales of hay on a 1900lb trailer a few days ago without an issue.

[darrininverarity]

I remember in the early 80s finding a Chevy 350 4bolt Quadrajet engine was no easy task, all we had was the wezzer 305 2 bbl.