What should I be using in a '83 SBC?

[Gene K]

Not exactly the same, the crank balancing is different between the two, 305's also had cast internals, and 2 bolt mains.


Not sure why the push for SAE30? This isn't 1983. Back in '05, I scored about 40 gallons of Delo 400 SAE30 from AZ for $.99/gal. It was a good deal and discussion back then revealed it behaved more like a 15W30 than straight weight. Still, not sure why you would not run a quality 5W30 lube in this stock 305. No extra ZDDP is going to save a physically inferior junk cam. As far as flat tappets go, there are millions of GM small blocks (and Jeep 4.0L/2.5L) engines running around on modern oil. I just don't see the value in running $12/qt oil in a 305.

Production engines of that era both had forged rods. 305 Rods were lighter (we have used them in 350 Claimer Motors for performance increase). Both had cast pistons and cranks. 2 Bolt Mains were common on Half-Ton 350's.

Many people have a low opinion of the 305 even in 4BBL form because of the heavy vehicles they tended to come in and rose colored glasses when it comes to older cars. They remember the old 283 and 289 fondly without considering unless they were solid cam engines they only made about 140 bhp net and came in cars as light as 2600 lb. It's not really fair to compare it to a 305 that is stuck in a 2,000 lb heavier truck or Caprice.

Even the 8.5:1 LG4 (150 bhp) runs better than the typical 283 in the same weight car. A 220 bhp TPI would give a 283/315 Fuelly a run for it's money in the same weight car.

 

[Zaedock]

Production engines of that era both had forged rods. 305 Rods were lighter (we have used them in 350 Claimer Motors for performance increase). Both had cast pistons and cranks. 2 Bolt Mains were common on Half-Ton 350's.

Thats right. I should have added "only" after the sentence but corrected it in a following post. i.e. 305's never had forged cranks or 4 bolt mains (insinuating 350's could).
305 rods are approx 30 grams lighter than 350 but the H-beam is weaker. Why bother running 305 rods when you can get 600 gram Lunati rods for $230 and perhaps use them with a 305 crank for less balancing effort or start fresh with a 350 4340 crank/rod kit for $1500 +/- and never worry about it. To me it only makes sense to use a 305 crank for a mild street motor on a budget.

 

[addyguy]

I find it funny people defending the 305; but even within the small sample of this thread there are several people who had them give up!
I will temper my comments a bit...later 305’s, about post-1987, seem to be a good engine. They did well in the trucks, and F-body 305’s with a 5-speed were pretty quick.
But 1977-1986 305’s were more likely to be junk than jem.

 

[350Rocket]

I find it funny people defending the 305; but even within the small sample of this thread there are several people who had them give up!
I will temper my comments a bit...later 305’s, about post-1987, seem to be a good engine. They did well in the trucks, and F-body 305’s with a 5-speed were pretty quick.
But 1977-1986 305’s were more likely to be junk than jem.

I have had an 87 with 200k, 89 with 332k, 86 with 150k that had been overheated and ran out of oil and kept going with perfect compression despite using oil, an 85 and another 86 in parts cars that still ran, and the original engine in my 84 Cutlass was a good running 305, and my current 83 305 with 240k miles. Also have a friend in sc with 330k on his 77 all original except a timing chain.

I didn't realize just how many I've had. Also growing up my dad had a 79 Impala wagon with a 305, the camshaft failed but he continued to drive it 3+ more years and it was still running and not burning oil.

Lots of friends in highschool had them too and I only recall one blowing up in a monte Carlo SS.