Looking to build a 283. Will be going in my 1987 pontiac trans am that is currently a 305 HO. any good cams that are recommended? Can I get 250 hp from this 283? Any good headers and y pipe kits? I don't need to worry about emissions.
thank you

 

Same as any other small block Chevy motors.

Sure. Plenty of em. Keep it small if you have stock gears and converter.

Sure. Eeeeeeeeeezzzzzzzzzzzy. Be aware though, the more HP you chase after, the less off-the-line torque you'll have, meaning, the SLOWER it will be on the street. Speaking strictly as someone who built a 283 back in the 70s (well, actually a 292, .060" over) when 350s were as new as the newest LT series VV8s are now, and got my a$$ handed to me by all of them. I put the 30/30 solid cam in it, and boy did it LIGHT UP at around 6000 RPM; below 4000 or so though, it was WEEEEEEEEK. Pitiful painful WEEEEEEEK. No idea what HP it made, this was back before they had invented dynos that people like me could get access to. It was in a 4-speed car with weeeeeeenie stock 3.73 gears so it was totally a SLUG off the line, took FOREVER to get enough RPM to wake up. Shifting down to1st gear at 55 mph driving down the freeway though, I had to frequently launder the pass side seat cover. So, choose wisely.

Frankly, in 2024/5, I would NOT do it again. It was problematic enough 45+ yrs ago; today, it'd be a total waste of money time and effort.

Didn't know that there were any L69s (the "HO" motor") in these cars in 87. They were still putting em in MC SS (my late little bro had one) butt not F body. Accordingly, I'm guessing you don't have any kind of "HO" 305. What are you REALLY starting out with? Even more to the point, WHAT DIFFERENCE DOES IT MAKE what motor you're taking out, to do the 283 downgrade?

 

My 87 trans am has a HO 305 with carburetor. It was the final year with the carburetor in these cars. I can take pictures of all the factory stickers in the engine bay showing what motor it is.

 

Some 87 f-bodys had the last year LG4 carb engine. 86 was the last year of the H.O. and there wasnt many then.

 

No need for photos.

What's the 8th digit of the VIN?

Not like it really matters all that much though if you're just gonna downgrade it to a 283.

 

The 8th digit is a 8

 

8 isn't the code for the HO 305. Pretty sure that's for a TPI 350.

 

Interesting this car has a carburetor so it's not TPI. There hasn't been any motor swaps either

 

Your 8th digit (well, character) is H.

That's the LG4, the regular non-HO 305, like everybody else that had a carbed 305 in their F body that year.

 

so in that case is a mild built 283 a bad choice?

 

Why such a small engine? You could build a "mild 350" for pretty much the same $$$ and have a considerably more powerful engine that is still very streetable.

 

everyone i talk to says the 350 is a boat anchor and should not be used

 

I see.


Good luck with your engine-building plans!

 

Generally, yes.

It suffers from EXACTLY the same problem that the 262.5, 265, 267, 302, 305, 307, and 327 do. Which is, the essentially IDENTICAL, widely available, and CHEEEEEEEP 350. None of those other smaller motors are "bad" in and of themselves; only, for "building", they don't compare to the cost-effectiveness of the 350.

MANY things interchange between the 2 engine sizes. They are, for all practical purposes, EXACTLY the same motor, just, with 2 different sizes of cylinders. Absolutely every part outside of the short block interchanges. You can use the same heads, cam, intake manifolds, carbs, exhaust, ignition, and so on, for ANY small-block Chevy, including the 400 if you want to go one better than the 350 butt stay within the same package. There's nothing about the 350 that makes it a "boat anchor", in and of itself, any more or any less than any other small block Chevy displacement, in and of itself; that term is more usually applied to the 305 these days, simply because it's the most common of the smaller small block Chevy motors today that are inferior to the 350. Back in the 70s when I started dabbling in this hobby and later did it somewhat professionally, the 283 and 327, and ESPECIALLY the 307, carried that distinction.

It costs EXACTLY the same to build a 283 as it does a 350. If anything, it costs MORE, because the few parts specific to it such as pistons and crankshafts, are far less common. A 283 weighs EXACTLY the same as a 350, is EXACTLY the same size, and suffers from EXACTLY the same World War 2 to mid-1950s technology level of development such as poor gaskets and seals compared to 2024 alternatives. However, it produces only about 80% as much power as the 350, if built apples-to-apples. (283 ÷ 350 = 0.80xxx) This means, in the simplest possible terms, that for every dollar you might spend on a 350, you only get about 80¢ of the value you would obtain that way, if you spend the same $1 on a 283.

It makes little to no sense whatsoever to spend MORE and in the end get LESS. We like to call people who do things like that, "different", and not in a complimentary way. It's like watching somebody go to the grocery store and see that T-bone steak is $15 a pound today, and the chuck steak right next to it is $8 a pound; and walking up to the butcher and telling him, "I want to be 'different' from everybody else. So charge me $15 butt give me a pound of chuck". That's EXACTLY what building a 283 (a size that was discontinued over 50 years ago due to its inadequacy EVEN THEN as compared to newer larger engines that cost the same to build butt deliver more results) in 2024/5 is. It's not much harder to see how much of a mistake this is, than counting up to 8.

So yeah, if you just REALLY want to be THAT KIND of "different", go right ahead.

 

I should mention also, that for VERY LITTLE more $$$ than just building a straight-up 350, you can turn one of those into a 383... costs about the same as a 283, but you get over 35% MORE for your money. (383 - 283 = 100, and 100 ÷ 283 is about 35.3%) That's not a factory size, butt parts are widely available in the aftermarket to make it. So in that sense, building a 283 would be about like paying T-bone price for white beans. "Different" indeed.

 

I'd like to hear more about these people who you're talking to, and I'd also like to hear how they differentiate the "boat anchor" characteristics of the 350, from the characteristics of the 283?

 

somebody needs to try a drag race between a '65 Biscayne 283 2 barrel/powerglide and a 1976 Monte Carlo 350 th350 2.73 rear and see who beats whom

 

Remove the smog junk from the Monte Carlo and my money is on it...

 

There's only one possible outcome, if the rest of the car/driver setup is also apples-to-apples.

Kinda like, the 69 302 was "rated" FWIW at 290 HP, butt the next year, the 70½ 350 "LT-1" was "rated" at 375 HP. Identical cam (178), heads (041), intake manifold (don't know the part # offhand), exhaust system, carb (3310), EVERYTHING down to the last part number, except the 350 had the 3.48" 350 stroke whereas the 302 had the 3.00" 283 stroke. Same block (010 usually) with the same bore (4.00") and same rods even, although the pistons of course had to be different. We all know the 302 was "under-rated", butt still...

 

Since 350s are boat anchors, and OP plans to build a small engine anyway, I suggest he find a '55 265 block and build it instead. He will then realize a weight-saving advantage over a 283 since the '55 265 block has no provision for an oil filter.

And as everyone knows, taking weight out is the same as putting horsepower in.

 

Everyone you talk to is wrong.