[19996Silverado]

Hi everyone,
I have a 1996 with a 305 vortec in it. I want to build a 350 to put in it that has some HP and torque, but nothing insane due to my budget. Can I get some suggestions on which 350 block, heads, pistons and cam and so on that I can get maybe 300 HP out of with out breaking my piggy bank? I have a great machine shop locally that can do the heavy lifting so to speak but will do the build myself. Currently I have the TBI setup and NC may require me to keep that for emissions or something close. For all I care, if it can pass a emissions test I have no preference, I know that a carbed engine would be cheaper in the long run.

Thanks for your suggestions!
Dan

 

[aj06bolt12r]

300 hp? Super easy. Just get a vortec 350 from a 1998 pickup and swap it in. A set of headers, good flowing cats and 2.5" dual exhaust. Very mild cam with low enough lift to prevent retainer to valve seal contact and a custom tune will get you 300hp all day long. Really a stock LT4 corvette cam should get you there. I'd bet you could keep the stock intake, injectors and PCM from the vortec 350 and all. Just need a custom tune. Should be very affordable and pass emissions all day long.

Honestly a bone stock 5.7 vortec with an edelbrock performer intake, decent carb and a cheap set of long tubes will make 300hp even with the tiny stock truck cam. Hard to make less than 300hp with 350 cubic inches and vortec heads.

 

[19996Silverado]

Nice, now I wonder if I could get a few more HP

Thanks for the response! This sounds easy enough to do. Finding a 5.7 vortec in this area will be a challenge but something I can eventually. Now i am wondering if I may be able to squeak out a few more HP with a little more tweaking. Any other awesome ideas?

Thanks in advance, Dan

 

[ericnova72]

If you have to stay with the factory TBI injection, that really limits your hunt for power beyond 300 hp.

 

[techinspector1]

The L31 350 is still one of my favorite motors, fitted to many different pickup trucks and vans from 1996 to 2002. Here's a wiki article to learn more.....
http://www.crankshaftcoalition.com/wiki/Vortec_L31_cylinder_head

I'm a carburetor guy and know little or nothing about EFI, but perhaps there is an aftermarket "hot rod" EFI system that could be adapted.

If I were doing this, I would find a complete donor that maybe got hit in the side and totalled. I would then use everything out of the donor, including the AOD.

 

[Tim C]

If it is a 96 and you're in NC in an emissions county, like Cumberland, wake, mecklinburg, etc where the bigger population centers are (I used to do state inspections) you have to keep a stock style computer system. The state machine is going to look for a vehicle ID number that matches the scanned barcode from the registration (to make sure the station is scanning the same vehicle). It's going to make sure the engine light isn't on and the emissions readiness or monitor tests have passed.

You can tune it so long as the tuning doesn't disable the readiness monitors, as many times do.

If you're in a non emissions county like Sampson or bladen or the trucks gvwr on the door sticker is over 8500 lbs like a 3/4 ton OR it's a 95 or older up to 35 years then it only needs a visual check, in other words it needs to LOOK like all the stock stuff is there like egr or cat converters. Doesn't matter if they are hollowed out or whatever, so long as they are visibly there.

I agree with the l31 and lt4 cam for what you want too. We just put a ramjet 350 in my dads 67 c10 last year which is basically an L31 long block with a different cam and rockers and a custom injection setup. Dad wanted a little more thump though so we swapped in an lt4 hot cam which has more lope than the stock lt4 cam. I had to do some custom tuning on that for sure. Fortunately 35 years old or older vehicles get no inspections in NC.

Sent from my HTC6545LVW using Tapatalk

 

[BogiesAnnex1]

Hi everyone,
I have a 1996 with a 305 vortec in it. I want to build a 350 to put in it that has some HP and torque, but nothing insane due to my budget. Can I get some suggestions on which 350 block, heads, pistons and cam and so on that I can get maybe 300 HP out of with out breaking my piggy bank? I have a great machine shop locally that can do the heavy lifting so to speak but will do the build myself. Currently I have the TBI setup and NC may require me to keep that for emissions or something close. For all I care, if it can pass a emissions test I have no preference, I know that a carbed engine would be cheaper in the long run.

Thanks for your suggestions!
Dan

A 1996 is the first year of OBD II vehicle control systems on GM trucks. The V8 engine you have is the L30, 305 Vortec, the other small block V8 was the highly desireable L31, 350 Vortec. Both use the sequential multi-port fuel injection system but there are injector duty cycle differences to accommodate the different displacements of these engines. A 305 to 350 swap would have to modify the computer to accommodate this any any other changes made to the engine , driveline, or exhaust. The simple solution is to get an engine from a 1996 thru 2001 doner truck having a 350 along with its computer as this will have the proper program. The problem will then be the vehicle identification and security system will not match your truck so without further modification will not permit starting the engine. The other way is to have your computer modified to run the larger 350 either way you go brings expenses to deal with either modifying the security system programming or the engine operation programming. Solving the programming problems is a cost additive exercise to the tune of several hundred dollars for any swap or modification that is beyond "simple". Changing to a carb if you don't have to SMOG is technically possible but still costly and does not eliminate the computer without a lot of highly technical work and considerable expense, especially if this has an automatic transmission.

1995 is the last year of OBD I which is a much simpler vehicle/engine control system, which is also pretty easy to swap back to a carburetor. 1996 is the watershed year syarting vehicles made to the Government's intent to thwart engine and driveline modification on SMOG certified vehicles.

I wouldn't even mess with this or a newer vehicle. The last year of simple trucks was 1986, theses are carbureted with a lot of mechanical SMOG systems that can be deleted and the engine modified back to pre SMOG performance with a little simple effort and modest cost. The 1987 through 1995 years are the first generation of On Board Diognostics (OBD); these can be messed with to a great extent for a modest cost. 1996 is the start of the second generation of OBD these are meant to keep vehicle modifiers out and they get increasing complicated with each year approaching today.

Bogie

 

[cerial]

Bogie is 100% correct. My last truck before my current 87 v10(5.7) was a 96 c1500. 87 has several hundred feet less wiring.

305, nv3500, 3.42 rear standard cab short box that I picked up for $1500 with 250+ original miles on it. With the only modification being a flow master
muffler and a k/n air filter. I fixed a few electrical issues and then drove it hard for a summer.

If you want some attitude put a stick into the thing. It really allows you to have fun with the 305. I took off in 2nd and would wind that 305 out frequently.

If you throw out the cast pistons you could run a 50 to 75 shot and "probably" still stay within emissions. Check with your local inspection shop. :mwink:

I ran a 75 shot on a 98 totally stock 305 several years ago for kicks. But that was a $600 ride stripped for going sideways.