283 vs. 350

[1Bad62Pro/Street]

Originally Posted by Hogsophist

Having this same internal question now! Love this site.

Bone stock 283 in my 57.
Th350 transmission
Rear end out of 79 trans am ( still not sure on the gears, need to open it up)

It drives fine. No leaks or smoke. Seems I have read these engines like running at higher rpms. Gas mileage is around 10 mpg, which is horrible.

Is this a good combo?
Is the mpg way out of wack?

Bring forth your opinions. I'm not a mechanic so all thoughts would be great.
Posted via Mobile Device

Thumbs Up!
1 hp per cubic inch - 3.875 bore.
283c.i./Th350
http://67-72chevytrucks.com/vboard/s...d.php?t=382583
http://www.chevyhiperformance.com/te...y/viewall.html


http://youtu.be/T87HNbYavnQ

[padresag]

Originally Posted by 1Bad62Pro/Street

Thumbs Up!
1 hp per cubic inch - 3.875 bore.
283c.i./Th350
http://67-72chevytrucks.com/vboard/s...d.php?t=382583
http://www.chevyhiperformance.com/te...y/viewall.html


http://youtu.be/T87HNbYavnQ

but not every 283 is 1hp per c/in. the 230 hp(the old p/pack eng) is a nice little engine esp with 4:11 axle and an o/drive
ron

[luvbowties]

Originally Posted by revjim

Need your opinion. I have two engines ...an original 283 195 hp. And I have a 350 LM1 engine. Both have auto trannies. However the 350 tranny had to have a fabbed transmission mount. The frame I want to use came with the original 283. What would you rather have? I am not so worried about power as I am dependability and ease of maintenance. Plus I am not wild about fabbing a new tranny bracket. Let me know.

I reckon it's time for my input. During many years of owning many '60's-'70's Chevy pickups (as I was in the used car business & specializing in pickups, using whatever eng. came in a purchase or installing whatever was conveniently available in wrecks)with different sized 6's and different size v8's(5 sizes of v8 sbc's), there is 1 thing I have noticed: none of them were what one would call good on gas. The range on the ones I checked was around 10'ish to 13'ish.

[[An interesting exception: There actually was one that I bought, from original owner, a farmer-friend, who told me it was good except rough on gas: was a 1973 longbed, 3-speed on column, a 6-cyl. with No p/s and NO p/b and even NO radio and NO leaks at all underneath--dry as a 'powder keg' was how we described them. It started perfectly cold and hot; accelerated smoothly as could be wanted both cold and hot. Had standard wheels and tires. Cruised effortlessly at 55, 65, 75, whatever the driver wanted. It got, at very best, 6 mpg! (This exception was intentionally excluded above in the 10-13 range!) I drove it to a town 60 miles away to pick up a windshield; put in 10 gallons as I was leaving which reflected on the gauge; before returning from that town, gauge showed E, so I put in 10 more gallons, which again reflected on the gauge. Was back on E when I got back to shop. Drove it home that nite, about 4-5 miles, and ran out of gas in my driveway. All this during higher-priced gas, about 1975-76. Got it to the sale, auctioneer asked discreetly what the least I would take for it--had it looking good--my reply was 'reckon we will get a bid'? i.e., it was on a 1-way trip!]]

So, my overall theory is that regardless of engine size, our boxy Chevy pickups are prone to poor gas mileage. And if the smaller, weaker engines get 13, why not get good power and maybe no worse than 10?...or maybe no worse than 13?

**Math is often funny: Gaining from 10 to 13 shows to be 30% better:3/10=30%. Yet losing from 13 to 10 is only 23% worse: 3/13=23%!

[63ChevC10]

Originally Posted by Pop's C-10

283..jus cause it a 283..

Amen to that!

[luvbowties]

Originally Posted by revjim

how do I tell what tranny I have...what ID am I looking for??

To determine if it is a powerglide, simply count the gear-detents at the selector on the trans--pg has P, N, D, L, & R...for total of 5 positions.

Six positions indicate a THM--either 350THM(squarish pan missing 1 corner) or 400THM(non-squarish pan).

To id all GM trannies, including metrics(having letters on pan) by pan shape, here is a good site:
>> http://www.nastyz28.com/chevy-transm...tification.php <<

[Project 1960 Apache]

What if tranny selector only has four positions=PNRD? What kind of auto trans is it?