Thread: turning stock 3800 into supercharged?

Hi Kyle, the bare block is about the only thing the same between the two engines.
-The supercharged engine has stronger pistons with a lower compression ratio
- different rods
- crank balanced different
- different flexplate again balanced different
- crank pulley/balancer balanced different and has an extra section machined on the end for running the supercharger belt
- cylinder heads have holes machined in intake runners for fuel injectors
- larger fuel injectors and completely different fuel rail
- cam sprocket for timing chain retarded 2 deg on NA engine
- intake manifold
- valve covers
- coil pack bracket and all associated sc belt pulleys and brackets
- transmissions has larger torque converter and differential, different gearing
- pcm to match the above differences

Many guys do what is called a top-swap which basically is using from the heads and up off of a supercharged engine. This will give you the topend but you retain your stock NA bottom end and trans and this requires custom pcm tuning to make work. There is a company ZZP that sells or used to sell modified lower intake manifolds and supercharger housings that allow you to retain your stock heads but cost wise you really arent saving anything, it just makes the job easier to do.

Top swap is $600 plus depending on where you get the parts and piece it together, or get a kit. You will make more hp than the gtp's becuase of the higher compression that the gt's bottom end comes with.

Here's a kit, but rather just use it as the parts list... look in the for sale section for parts, you could go to the junkyard and get these also...
W Body Store Supercharger Conversion Kit

Just buy a GTP engine from Ed or a junkyard and drop it in. Less labor and time involved, unless you were planning on having heads and things reworked anyway.

Most places that part out a swap kit want around $1k for the parts. You can get a whole L67 for around $600 with decent mileage.

Originally Posted by RooK

Just buy a GTP engine from Ed or a junkyard and drop it in. Less labor and time involved, unless you were planning on having heads and things reworked anyway.

Most places that part out a swap kit want around $1k for the parts. You can get a whole L67 for around $600 with decent mileage.

the point of this is for the higher compression, not the supercharger. if you just want the blower then an l67 might be the way you want to go as its easier by a large amount.

if youre good at finding parts you can do this entire swap for less than $600 including the gaskets and sealants you need to buy.

i wouldnt attempt this if you dont know your way around the engine.

has anyone here tried this? if so what are the gains you are seeing? is it worth the effort?

Plenty Impala owners have done it. One guy is down to 13.76 on a 3.4". Not really many other mods.

i did it. it was fun for the three days it ran. (forgot the oil pump gear for about 30 seconds of startup, spun bearing 3 days later)

its a lot of work. if you dont know how to work on a motor, find someone that does or pray that you are meticulous enough to figure it all out and do it right.

Why were you messing with the oil pump gear on a top swap?

put in a double roller and cam. didnt realize the jp was a two piece setup and slapped it back together without realizing it. first few starts, no oil pressure. by the time i got it back together it was halfway gone already.

it drove for three days after that before i spun a bearing, just to show how tank-like these engines are. wish i would have kept that cam..TEP is MEAN!

Well, that shouldn't factor in on a regular top swap then. Most wouldn't even open the front cover.

no doubt.

i might hit the yards around here and buy a NA bottom and then the SC top and assemble this on the stand. i wouldnt do this with only one engine (in the car already) on hand, too many variables