I am starting a long-term build surrounding a 5.3 junkyard engine.
The car will hopefully be an "old school" mid 60s to early 70s GM Intermediate and/or possibly even a full-size body. I am considering a 4L80 and probably a 12-bolt GM with a mid-to-higher "3" series gear set.
The car's primary use will be for fun, cruise nights and some dragstrip fun. I also like to move quickly from stoplight-to-stoplight and it always seems the guy next to me is trying to do the same thing...???..go figure..??
The car must be totally streetable and something that can be taken on a road trip without a full day of pre-preparations, room in the trunk for a large toolbox and spares, etc....
I think you get the picture..
My performance goals are budget and reliability. Keep in mind that although I am not a genius with wrenches, I make fair self-assessments and hand the wrenches to someone else when I'm in too deep.
in addition, I work at a Chevrolet dealership and I have gearhead friends who I trust would lend a helping hand if asked. Also, the employee discount on GM parts and GM Performance Parts is phenomenal.
My first step is in obtaining a used 5.3 and is where I have a few questions.
My output objective would be in the high 400 to possibly 500 horsepower range. However, I am more interested in a long hard torque curve instead of a peak horsepower number that occurs within a 50 RPM range just before the valves float....
i am unsure what expenses I would inccur on the cam, heads, normal aspirations or if turbo charging would be the answer. Remembering that it will probably be a higher mileage engine with a stock lower end, I would think single digit boost would be all I would like to gamble with if turbocharging is the greater value.
First off, is there a more favorable 5.3 engine assembly to obtain...??? For example, RPO L59, LM7...etc.
i am definitely going with an iron block so I need to know if their are any preferable RPOs than may contain parts more favorable over others.
What should one look for when purchasing an engine, more favorable place (junkyards...Craigslist...) than others???
Once the engine is obtained, I am sure I will have a whole set of new questions.
Thanks

 

Check out Joe Novas posts/threads regarding pull out
5.3 with turbo 10-12 Lbs on a factory 5.3, later the better but
He will have specifics. Easiest, Most Econimical, & Reliable
500 RWHP for your goals.

 

You want tq you are limiting yourself with a 5.3l BUT there are a few options. First off gmpp doesnt hold a candle to any aftermarket parts. I sell and use both, its very lopsided. The ls7 lifters are good. That's pretty much it.
05+ lm7 have the floating pin pistons which are better to use. Id make an iron 5.7 out of one. The 799/243 heads would work best for stock power, they are cheap anywhere used pretty much. They come on the l33 and lh6 but both are alum block and limited on bore size.
Then get a nice custom cam, use flat top 3.905 pistons, gm mls head gaskets ls7 lifters, dual spring kit and youll have 500ish crank no problem. Ls1s with 241s ls6 intake and headers amd a high 220s cam make above 400 all the time. That's roughly 480 crank or so. 5.3s have more of an issue. Small bores wont make as much power na.