99 Silverado 3 door

My 99 Silverado has a 5.3 Liter with 220,000 miles on it and runs like a champ. Starts at -20 degrees too! It's up over 222,000 now. No oil burn. Tranny doesn't slip. 4 wheel drive works like a champ. I only get around 14 mpg with it but I'm not complaining. It's a truck and I love it.

westgl

My 99' Silverado w/ 5.3L /325 C.I. reg cab, short bed, 4x4 Z71

It has 155K total miles, I put on about 3K so far, engine does not use any oil and runs strong

Jacob Stutzman

I have a 5.3l in my silverado now and want to get a replacement engine because mine has 206k miles on it. If im going to replace the engine im thinking about going up to a 5.7L. My question is will it be an easy swap and will it bolt straight up or do I need to change the mounting bolts and will it bolt straight up to the tranny? Will the tranny work with the 5.7L and what else will I have to buy to swap that engine?

JK23112

Wouldn't going from a 5.3L to a 5.7L be a step 'backwards' for you? The 5.3 is a more modern design, has the "coil on plug" ignition system (rather than distributor) and develops more power per cubic inch. I think there might be some internal engine design changes, but I am not sure about that.

Either way, though, it is still a small-block Chevy and both engines should serve you well. :-)

westgl

I have to agree the 5.3L engine is a good engine, Mine runs great.

I have had both a 97' silverado Z71 with a 5.7L, and my current 99' Silverado Z71 With a 5.3L, the 5.3L seems to be a more Lively of a engine.

I call my current 99' 5.3L Z71 my corvette truck.

The 5.3L is a rev happy engine.

If you put a 5.3l back in it, it will be much less head ache and Pain, less $$ too.

GuyGene

A friend has a Tahoe, don't know the year, but I think after 2000, with 385,000 miles! Engine never touched other than normal maintenance. I like that!

ByrdGirl

I own a 1999 with a 5.3L in it and the the miles exceed 238,000

drae150

I have the 5.7 in my 01 express 3500 cargo van. Still fires up and runs strong with 295,000 miles on her. Lifters are now starting to tap and it burns a quart of oil every 1, 500 miles or so.

mdub80

first off im new to the forum and new to building chevy motors ...i have brand new chevy proformance large port heads and the max lift is around .430 or .470 ... im trying to get a .555 out of them ...is it just as simple as changing springs ... or do i need to machine the heads

thank you so much for any help

gotplacestogo

I've been driving a Z71 with thr 5.7 Vortec for 440,000 now on the original never overhauled engine. It's still going but can't last forever. Still gets 16 MPG. One qt of old every 7500 miles. So thinking now about going to a 5.3 engine on a 2003 Z71. So I get a kick out of reading so many posts, which have helped me so much over the past few years (thank you all ), but they're only talking about 200,000 miles or so. Oh, and by the way. I only use BFG AT KO tires and I haven't had an alignment done in over 200,000 miles and always get over 60,000 miles out of them. Been over Black Bear and Imogene Pass several times.
So it may take me a while to properly review the 5.3 compared to the 5.7. You know, maybe 2023. Thanks to all for the thought.