i have a 1990 RS with a 305 TBI which i wanna take out and put a 350 in.
after some research and talking to some people im getting conflicting stories.
MY mechanic told me i could buy that 350/290/HP crate motor and an eldebrock tbi intake manifold and that i could keep the TBI that way.
But the guy at the JEGS tech line said that is not true that, that motor is made for a carb only and it wouldnt work right with that tbi manifold. Is this true what will work.

I also found somebody who has the exact same car as me and did the same swap except he bought the base 350 330 HO. and a GM TBI vortec manifold, and the holley 670 tbi unit. and his seems to be fine.
Can anybody tell me if this will work, and if so which engine should i go with

the 290 HP with the eldebrock tbi manifold, or the 350 330 HO with THe GM TBI vortec manifold.
thanks for any info at all.

 

you should be fine, the only reason hes (jegs tech support) saying that is because of the cam, so that might need swapped. and a custom chip to make everything work right.

 

so what kind of cam would work, and should i buy the crate motor as it is and then swap the cam?

 

Does anyone know anything else about if this will work or not?

 

usually thats what you have to do, buy the engine and swap the cam. if you goto the comp cams website they have a program you can download and put in all your info and it will give you different choices of cams for your app.

 

That cam won't cause any problems with TBI.

The TBI manifold center two mount bolt holes will have to be modified to bolt to the heads, though.

 

So fiveseven kid which crate would you go with
the 350/290 hp with and eldebrock preformer tbi intake manifold

Or the 350/ 330 HO base package with the GM TBI Vortec INtake manifold?

and do you have any idea how many HP the L31 has?

 

Haven't we been through this already?

The budget 350 on the TBI forum.

 

That cam in the 290 HP crate is 224/224 a little big for a speed density TBI setup or even TPI setup without DIY Tuning. The GM 330 HP HO is a MUCH better engine thatn the 290 HP DOG. The STOCK L31 is better than the 290 HP crate and I would actually choose the Stock L31 over the 330 HP HO. The Stock L31 comes with a roller cam and hardware where the 330 HP does not. Otherwise the 330 HO is the same as a the two bolt main L31. Same block, heads, pistons, crank, rockers, pushrods, tin, etc.

 

Although not necessarily always the case, I assume DIY tuning with SD anytime you plan performance upgrades with that type of system. The statements made prior indicated those making the statements were saying the system couldn't be tuned properly with that cam, which isn't true.

 

hey fast 355, so you say the L31 and 330 HO crate motors are the same except for the roller cam in the L31, does that mean that the L31 has as much horsepower as the 330 HO?
i read the budget tbi buildup and am looking to swap my 305, but i dont know how to tune the computer. im going to have a shop do the swap and as long as i get the right chip, they should be able to tune it up, right?

one more question, if i stayed with the roller cam that comes with the crate L31 and didnt swap it for an Lt4 cam, what kind of horsepower am i looking at with hooker 2460s and a magnaflow catback with no cat?

any other info you could give me about this swap would be great.

 

does anybody have any advice on this, what crate motor shoul i go with,
the L31, or the 350 330/HO, and does anybody know what kind of horsepower the L31 has out of the crate, i want to get up to about 300 HP
will i need to put a cam in it to acomplish that. And will the HOlley 670 cfm throttle body be enough for either or theese motors? any info would be greatly appreciated.

 

stay away from that cheap 260hp or 290hp crate engines. Those cam designs are like 40 years old and are horrible. Get an engine with roller cam with a new design for sure. I cant exactly recall where i read about the gm crate engines but somewhere they were talking about the power curves with them. The curves were majorly improved by installing a new flat tappet cam design. It was almost like gm was just getting rid of the old junk cams and or they are like penies to make or somthing?

 

I agree. I have the flat tappet cam primarily for cost and would like to upgrade to roller cam for better reliability and performance.