I have a 1990 RS with a 305 tbi in it and im gonna swap it for a 350, ive decided to go with one of theese 2 engines, both vortecs, so i will be able to use that GM tbi vortec intake. i want to get to about 300 HP and want to redo my 700R4 as well, ive already got the headers and the magnaflow exhaust, and upgraded to 3.73 richmond gears and posi traction. i was wondering if i could get some feedback on which way to go, and what motor.
and if i buy the L31 New i would be putting a new LT4 cam in it like the sticky tbi buildup article suggests. any feed back from anyone?

 

Keep in mind that the stock vortecs are VERY limited in terms of lift. .450 is the very max ammount of lift you can get. Over that and the retainers come into contact with the valve guide seals. If you swap out to some comp-cam beehives and offset retainers, you can get a little more lift. IIRC, they moved the max lift to around .500 or so at the exhaust. With different exhaust valves that dont have the pressed-on hardened heel, you can get even more, but, with those springs, you run the risk of pulling the studs out.

These where some of the reasons I decided shelve my old vortecs and to go to aftermarket heads for my next build. More selection in terms of springs and you can run the low profile teflon valve guide seals that allow for lots of lift.

If you want to just swap in a motor and forget about it, the 330 HO is a good motor. The cam profile is a bit antiquated, but it should make decent power once its tuned.

 

anybody else got any ideas, or what motor would you go with?

 

I've heard that the max lift is more like .475 with the vortecs?

 

It varies from set to set, but the pair I have will only allow for up to .450" of lift. After that, the retainers come into contact with the seals.

 

Use the short block and add the heads and cam you want.

http://www.sdparts.com/product/12556...kAssembly.aspx

 

Get the vortec heads from sdparts that already have the springs and headwork to run a decent cam for under 600 I think or go ***** out and get some aluminum heads for 1200.

 

If you have the heads off of the engine, why don't you pull out the studs, mill off a little of the stud bosses, and put in any cam you want after installing some screw in studs?

 

The L31 is a roller cam motor and the HO motor is a flat tappet. For that reason alone I would go with the L31. You could also do the year one vortec motor. It already has the hot cam installed in it and the vortec heads modified for the larger cam. It's a sweet deal for only 3k

http://www.yearone.com/serverfiles/f...8&cat=G&trk=22

 

i believe that the 330ho crate engine has been used and there is a tbi kit sold for it that is bolt on. i believe the unit and the computer. but that is more dough. i believe that the 330 would be b etter as for a performance engine right now.

 

I have a 91 S-10 with a 350 in it and i am running a 330 hp vett roller cam with sawtooth vortec heads and 1.6 roller rockers and a CFI. Took some work to put the CFI on the heads but never had a problum (till someone stole the truck all that was missing was the CFI and the tires) think the lift was like 4.65 or sumtin like that. with the 1.6 it is close but works fine till the chip witch is set at 6200
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