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7.4 454 ?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by wheelin247, Jan 16, 2001.

  1. wheelin247

    wheelin247 1/2 ton status

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    im thinkin about buyin a new 7.4 454 it will be a stock one becuase ill put in better things before i put it in the truck but how much horsepower and torgue is in a stock 454 ?....i heard all different ranges ?...thanks
     
  2. JimmyDie6.2

    JimmyDie6.2 1/2 ton status

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    there are all different specs because there were many many different combinations. I won't list them all, but here's a few. starting in 1970 for the first 454 you could get a 450 horse LS6 454 closed chamber rec. heads in a chevelle and over the counter, or a 365 horse LS5, offered in the chevelle full size cars the vette, etc. you could get a truck motor 454 with less horse...300 I think. last year for the 454 in the vette was 74. it had if I remember 250 horse, small heads oval. Before the feds got involved chevy even made an over the counter LS7 with a rated hp of 460, but it was more like 510. open chamber rec. headed motor (the lower HP numbers represent lower compression ratios because of emissions requirements) cars had the 454 last in '76 I think. trucks had them every year except, 82??? something like that. customers really bitched in that year because the small block was underpowered for heavy duty jobs. 454s for trucks after 1976 were rated at 190 horse and 240 ft. lbs. of torque, until like 84 then. with better fuel management and computer generated cams, and cleaner fuel, GM uped the HP to 210 with more torque, like 300. as time went on and the gen IV BBCs turned into the gen Vs, in 1992???? the 502 was born, which is the 454 crank in a big a$$ block. Basically you can have any amount of HP from a BBC. my advice is to avoid all rectangular port headed motors, they are for race cars, try to find cast #049 cylinder heads, they are big valves, 1.88 -2.19 like those recs mentioned, but they have oval ports for increased lower rpm velocity, this make s a perfect truck head. 454s came 4 bolt blocks galore and steel cranks, most steel crank motors are early 70s vintage though. I hope this post helps you, I don't have my BBC books with me. So all the info here is from a shot memory, so if there is anything erroneous posted, I'm sure the guys here will fix it up, but thats the basic scoop. Go do research, the library has shelves of engine books, filled with casting numbers, hp ratings, applications...........................js
     

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