replacing 350 for a454

[boti4ever]

I've heard that it was'nt much of a hassle replacing a 350c.i chevy for 454 into my 1tn 4x4 chevy pkup.was told that i needed to move my motor mounts and that everything else bolt right up.Please help me to do this the right way .Thankyou for your time into this matter

[bduff509]

If a 396 is the same block as a 454 you may not have to move anything. My son & I just pulled a 350 & stuffed a 396 into his '80 Camaro &, outside of the tight fit, it went right in. You may have adapt your fan shroud as I believe the 454 is going to sit a little higher. He's also going to have to go to a 'vette style hood for clearance but you won't have that problem with a truck. I had a 454 in an '80 Suburban. I got about 6-8 mpg. It's a great towing motor, lots of low end torque but, if it's horsepower you're after, you're better off with the 350 unless you want to spend an obscene amount of money.

[okie-chevy-man]

i have to disagree with you on that. a big block wont fit right in the dimensions are different as well as the location of the motor mounts. and you must not have modified ANY engine if you think you can get more HP out of a 350 then a 454.
boti. it mainly depends on the year. 87 and older you wont have too much trouble, 88 and up went to fuel injection so its ECU controlled. for more info send me an email.

[bduff509]

So far, the 396 is in the car & the only thing that didn't fit was the throttle cable. It's a little short. The mounts weren't touched. Looking a little closer, it's not that the engine sits any higher that the fan didn't fit. The fan that was on the big block is about 19 1/2 in. & the shroud is sized for the 350's 18 in. What I meant about the comparison of H.P. in sm. blk. to big blk. is that, dollar for dollar, it's much cheaper to build H.P. in a 350 than 454. If you can effectively argue against that I'd like to know where you're getting your parts from. I have built several 350's & thought long & hard about working the 454. I'm not going to spend that kind of money just to say I did.

[2001BlackSES]

You don't need to move you're motor mounts, but you need to purchase the ones neccessary for a big block. The big block motor mounts should use the existing holes in your frames crossmember. Should bolt up just the same. This is the beauty of Cheverolet! Oh, and no matter what your trans is assuming it is a Chevy trans, the small or big block will bolt right up to it. For bduff509: the 396 is exactly the same block as the 454, pre 86 of course. I'll be dropping a 454 into my 78' Blazer and re-gearing to 4:56's next year so I can turn my 40" mud tires adequately.