i want to put a 5.3l in my 88..ill be building the engine from the block up..ive already did the v6-v8 swap but i want somthing diffrent n this is the way i want to go..any input would b great...i would like to know as much as possible..my questions r mainly about the engine tho..being LS based will motor mounts and headers be the same as a reaguler ls motor? well like i said any input is wanted so please help me out

 

why? You have a 350, and you want to sink huge coin into building a 5.3L motor, which I don't think has a huge aftermarket, especially for the bottom end, just to have a smaller engine? If I was going for an LS motor, i'd want to take all the cubes I could, just to keep it many many legs up on an old school SBC.
Yep, being LS based, it'll be the same as regular LS motor..? I think you maybe made a typo there?

LS style parts are notorious for being retardedly expensive, due to their relatively small market right now. I'd just soup up your 350 right now, unless you were wanting to go all out for more cubes, and high tech computer controlled stuff.

 

I would too like to do the 5.3 or even the 6.0 swap since ther $1000-1500 cheaper than the LS1's. I have done some searches on here and it will require all the same stuff that the LS1 mounts,crossmember................. you get the picture so keep us posted on it.But like Sonix said there is not alot of after market for them. GOOD LUCK!!!

 

Car craft I believe did some dyno tests on a 5.3 Avalanche and upgraded the rockers, intake trac, and exhaust. Pulled close to 290RWHP and 340 TQish. Now, throw a set of Headers on there and with a F body not being 4x4, more power should be made.

 

No replacement for displacement

 

look @ ls1tech's website under conversions and hybrids. They have alot of info on Gen III & IV swaps into all kinds of vehicles. Yes, the 5.3L v8 is structurally the same as any Gen 3 motor. All external parts will bolt on if not mistaken. the only difference in displacement for 4.8/5.3 is stroke and the difference in 5.3/5.7LS1/6.0 is the bore sizes. the 4.8 & 5.3 actually share the same block and you can bore one up to equal an LS1. Thunder Racing has alot of parts for these engines and yes, theyre not cheap but if you have the money to do an LS swap to a 3d gen then you should afford the parts. Check out those sites. Good luck with the swap!!

 

oh yeah, Hawks 3d gen parts has a LS Engine swap for the car!! You need different headers and Mounts from what I know. I cant remember if you use an F-Body oil pan or if you need a truck pan but you should probably get an LS1 intake manifold (LS6's flow better and are reasonably cheap.) I think you'd need an LS1 fuel rail though.

 

youd also need custom headers to fit the 3d gen, Hawks 3d Gen Performance has an Ls1 conversion section for the car. I cant remember if you can use the truck engine oil pan or not (may need an Fbody pan) You may also want to get an LS1/LS6 intake manifold (LS6 manifolds free more power) but I think youd need the LS1/6 fuel rail. Youd also need a PCM for the engine if you plan to keep FI or you could always go the carb'd route.