Rebuilding small block chevys.....

[BIGCHEVY4X]

Ive got a few questions about small block buildups and i hope you guys have some answers. Basically im trying to do what everyone else is....build the most power for the least amount of dough. Ive built a few 70's and 80's smallblocks but nothing newer and thats what most of the questions revolve around so feel free to chime in if you guys have any answers.....

what years are the Gen 1, 2, 3 Engines? And What changes were made? And what do the Lt and Ls designations stand for?

next is how do the vortech blocks compare to the older style? Can you put vortech heads on an older block?

What are the pre vortech motors?

Im also trying to figure out what years the intake bolts changed. I know the older motors were all at the same angle then the four center bolts were changed to straight up and down and then they went to four bolts on each side right?

I am planning on running these motors on a pre smog carb truck So i need the adapter manifolds. I know that you can oblong the intake bolt holes or get a diffrent manifold but do anyone make an adapter manifold to go to the 4 bolt on each side style?

I have been my engine kits from Northern auto parts and i have been pretty happy with them but i was currious why the later model kits are like 600 bucks for a master kit and the 69 to 80 blocks are like 3oo. Thats why i was thinking of building up an older block and putting vortech heads on it. I also noticed that they dont sell kits for motors newer then 2000.

Anthor question I had was what you guys thought about a vortech motor with a bigger cam and better pistons with like a roots type blower compared to dumping alot of money into building a motor without a blower. How would they compare roughly power wise and money wise?

Does anyone have a list of casting numbers for newer blocks?

Im also looking into building a 383. ive seen kits with pistons and a crank for like 700 bucks but that seems pretty cheap. How much maching goes into the buildup. I know th block has to be notched but is there anything else out of the ordinary?

Someone told me that if you change the cam to diffrent cam then you have to change the valve springs also.

I think the way to go is with a big block but i dont have any right now but i do have a few vortech motors and older blocks laying around to play with.

I really enjoyed building the motors that i have built and i want to build more just for the experince. I dont have alot of money but i like doing everything myself. I allready have decent motors in both my blazers im just trying to learn more. So thanks for any information and feel free to add anything intesting. Thanks
Andrew

 

[dremu]

Some general nomenclature:

LT and LS are GM RPO's for specific motor families; generally followed by a number, i.e. LT1 or LS9. IIRC these motors most often show up in the Corvettes and Camaros.

Vortech, with the H, is a brand of aftermarket parts -- blowers, IIRC.

Vortec, without it, is the GM intake type. This would have started waaay after I know anything about, like in the 90's sometime (newfangled! )

As for casting numbers, I think everything you could ever want is on

http://www.mortec.com/

HTH.

-- A

 

[4X4HIGH]

The common SBC started in 1955 and went pretty much unchanged until 1985, starting in 1986 GM went with the 1 piece rear main seal and in 1987 GM changed the 4 center intake bolt angles and also went with center bolt valve covers. That combo stayed the same up through 1995 and then starting in 1996 GM came out with the vortec V/8 which is basically the same lower end with a revised head design with only 8 bolts for the intake manifold that were 5/16" instead of 3/8" like all previous years. Beyond the vortec engine i haven't kept up on the engines but i know that the LS series was the next engine GM played with.

 

[bowtiepower00]

Gen I is the SBC you're familar with. Gen II refers to the LT1 and LT4 engines, in cars. Gen III is the LS series engine, which is the new generation SBC that was intro'd for 97 (vette), 98 (car), and 99-up NBS trucks. The Gen III's are completely different than the earlier motors, metric fasteners, O-ring type gaskets, etc. The Gen II and Gen I stuff can be mixed to some extent, the bottom ends are the same for the most part but the top ends are different. There are Carb manifolds available for all of them.