Is this getting old

[GSD]

Sorry for the re-post

In the process of buying a 80 chevy sb 4x4. Overall pretty nice truck
except for one thing kinda buged me. The truck has a 5.7 and when I drove it it didnt seem to have the get up and go that you would think it should have. From a dead stop if you were to stomp on it the rear tires will barely screech. The od says 69,000 and they say its true miles but im doubting it and thinking its 169,000. Is there anything I can look for performance wise to make sure this is not just a old tired engine? I have had 5 of these trucks over the years and they all seem to run alot better.


Thanks
Jason

[KShortell]

I can't say for sure, but I'd guess this: 1980 was the peak of the old-school smog controls that restricted power. I know the Corvette 350s of that time were some of the weakest ever produced. Mopar Slant 6s were using "lean burn" and also a bit down on power. Combine that with a tall rear end gear ratio and you have a real dog performance-wise...

[79BIG10]

Check the heads and block for casting numbers. This is a dead give away to see if it's a replacement engine that could have been rebuilt. If it's the same numbers then it still could have been rebuilt but hard to tell without pulling the oil pan or the heads. If you want to upgrade it even with a older engine you can install an aluminum intake, rebuild or replace the carb, and install a new HEI and wires to help wake it up. These are a good project to help it out.

[1FaastC10]

Originally Posted by KShortell

I can't say for sure, but I'd guess this: 1980 was the peak of the old-school smog controls that restricted power. I know the Corvette 350s of that time were some of the weakest ever produced. Mopar Slant 6s were using "lean burn" and also a bit down on power. Combine that with a tall rear end gear ratio and you have a real dog performance-wise...

on the contrary, towards the end things were better. the worst of the worst was from 1972-1974. 145hp was all they could muster. i had one in my '49 Chevy with 3.08 gears behind it, and a TH350. even the low hp engines would break the tires loose.

[SanitysBane]

in 1977 a 3/4 with a 454 was the fastest cat around, it had NO emmsions on it, last year they could get away with it.

[GSD]

I ended up taking the truck to a shop to have it checked out before I bought it. The guy checked it out and said for the age its in really good shape. Just the average oil leaks but not to bad. The compression was a little lower then what he would like to have seen but it shifts and drives straight. I drove it home tonight on a 45 min trip doing 65-80 mph and drove solid. best 65.00 I spent. I am going to look at replaceing the carb and HEI and doing a tune up. The carb runs a little rich. I will post pics ASAP.

Thanks
Jason

[N2TRUX]

Just so you know the 1980 350 had 175 HP/275 TQ which was up from 1979 that had 165 HP/270 TQ.....

[Russell]

My 80 3/4 ton can't even chirp the tires if I floor it off the line, I can get it to chirp em if I use the brakes, but she won't keep spinning them. My truck has been totally desmogged now too, still runs weak though.

[screwballl]

my 76 was the same way, i am in the process of replacing a few things and had a few replaced already. Got a Edelbrock 600cfm carb which basically doubled the power (or at least the "feel" of it), replaced the fuel pump for good measure, also replacing the HEI which has been giving me problems, not starting soemtimes... but just the simple carb swap (not optimized yet) has allowed me alot more of what i wanted.
Also it is easy enough to check the casting numbers and also the first letter of VIN gives away the engine, for example mine starts with T which came with a 2bbl inline 6... but i have a 350 so i have no idea where this engine came from, but i liek it

[1FaastC10]

i think what you guys are referring to as "weak" because it wont chirp the tires is actually the truck putting more power to the ground. 3/4 ton trucks usually come with 4.10+ gears in them, thus the driveshaft is spinning 4.10 times to every 1 rotation of the tire, whereas a half ton commonly has 2.73 or 3.08 gears. the tires cant keep up with that kind of rpm. besides, who wants to spin the tires anyways? that's just wasted power. most decent street cars/trucks will not fry the tires off the line, they just hook up and go.

[Russell]

hehe, unless 0-60 in 10 seconds is good, my truck is a bit weak, lol

[RockHQ]

0 to 60 in 10 seconds is actually pretty well for an old, stock truck.

[cliffsta]

yeah, the 1980 305 came with like 145 HP and 265 LB/Ft, or is it 280 LB/Ft? i heard 280, but according to N2TRUX the 350 only gets 285 (using ONLY in a loose way). That's what i love about Ol Red. I know these things weren't rockin the boat with HP, but its that pretty Pound Foot of Torque reading that i like. HP doesn't throw you into the seat, thats torque baby!! And i know since i'm minus all the smog except that clogged cat my torque is decent considereing im keeping it real with near 150,000 miles.