TBI friendly performance 350 build ???

[PlumCrazy]

I've had no luck with the search tool. Sorry if this has already been covered.

 

BTW, I'm new to the forum.

 

Current config

1988 K1500 4X4 5 speed, orig 305 replaced w/ 350, stock heads, intake, holley TBI, Hypertech chip

Flat top pistons and Rv cam.

 

It's time to rebuild the 350 in my truck and I was hoping that some people could chime in with recommendations or input on where I might find some specs.

 

I mostly just want to do bottom end work to get it running again and build it so that it can grow into upgrades later like head work and headers.

 

What kind of build can this computer tolerate and still be street friendly? Approx budget $1500.

Comp ratio?

Cam specs?

 

Recommended Clearences? - deck clearence, mains, rods, rod side, ring end gap, oil pump tolerances.

Recommended hard parts? - pistons, ring stack, bearings, head gaskets

Recommended upgardes? Maybe intake or headers.

 

I'll most likely be keeping the stock intake and exhaust manifolds though unless they would amount to big $$ to power gains.

 

Thanks for your input.

 

Ian

[Cool Zr2]

You converted a 305 to a 350 for you replaced the 305 with a 350?

[PlumCrazy]

Yes. I replaced the original 305 with a 4 bolt 350 and installed flat top pistons and Comp cams 12-402-4 cam. 212/218 - .444 lift and lobe sep 114. It was always kind of quarky, not sure if it was too much cam for the MAP.

 

This was my first build and after about 70K of driving it like an Indy car and a recent oil pressure failure, the bearings are wasted. Hence, time for a rebuild to get it going again.

 

I edited the origianly post to say replaced.

 

Ian

[rascal]

ever thought about vortec heads? they are decent cheap upgrades. as pulling after market heads. not sure how they'd mount up to the stock intake, but eldebrock (spelling) made an intake that would mount them to a 4bl carb so I'd guess they'd make one for an tbi. I was alway taught in the backwoods academy that you should build the top if you build the bottom, or maybe that was just you should build the bottom if you build the top. /shrug something about it caused the one that wasn't built to leak worse due to increased pressures. guessing you pull with this truck, so if you go headers go long tube small dia. correct me if I' wrong.

[maroonsilverado]

i don't remember my cam specs off hand, but i went with the edelbrock performer cam, the one for a computer controlled vehicle. it's too small in my opinion. i can't really tell that much of a difference over the stock one. i met a guy not too long ago that was running a pretty mean cam in his 93. said he had to unplug a few sensors to get it to work right, but i couldn't get out of him what he did exactly.

 

im running a 9.5:1 ratio using speed pro forged pistons.

 

using stock heads with new valves. and had the stock intake and heads ported/polished. im planning on buying some new heads and intake in the spring, but the current top end isn't that bad on power.

 

if you're looking for some low end headers will help ya out, but when you buy gaskets don't get cheap. i was running headers before i rebuilt and i had to change the gaskets pretty regular. it's a VERY large pain in the butt to have to do that on a regular basis. but i know people with the same engine that bought "dead soft" copper (i think that's what they're called) and they haven't had a problem. so go figure.

 

if you upgrade your ignition don't get accel stuff. i went with accel for my entire ignition and i'm regretting it. their remote mount coil left me stranded one day for 45 minutes......i was pissed to say the least. i'm working on buying all MSD stuff to change over to.

 

i've had good luck with a cold air intake, chip, and underdrive pullies for some minor performance parts. a couple more serious parts would be some 1.7 ratio roller rockers and some roller lifters.

 

im not sure about the clearances because i didn't completely assemble my engine, and all my bearings and gaskets came in a rebuild kit. i also used the stock crank and connecting rods...i had them checked out and they told me nothing was wrong with them. so i just reused them

[NOS#9BIGMAC]

ahhh crap I just put on new accel plugs, wires, cap and rotor and my truck is running like a p.o.s. for some reason I think the plugs are junk

[maroonsilverado]

i didn't use their plugs. i went back with the delco plugs, but i did use their wires, cap, rotor, chip, and coil

[sstruck383]

To answer your question about the cam, the MAP sensor on TBI's is very sensitive. So a custom chip and injectors and needed. A cam that big will need a good bit of work....I have recently talked to Crane Cams about camshafts for TBIs for my 383 and they said they wouldn't go above 204 on intake because of the MAP sensor.

[357mag]

www.thirdgen.org check out the tbi forums and the diy prom forums. You'll be amazed at the amount of info they have on their site. You won't be disappointed...

 

Tim sends

[cedjunior]

Crane Cams POWERMAX 2030 is a very popular cam for TBI guys.

[Matt99Z71]

The TBI equiped 350 is probably one of the smoothest running smallblocks

produced. I have that engine in my work van, and I swear to god at 172,000 miles, I still can't tell its running at idle. When the truck finally rusts away, I'm taking that engine and 4L80E combo out for a killer offroad pickup. Going from 305 to 350, the injectors are probably a different size too. Besides that, I'm sure most of it is computer tuning. Your best bet would be a crate motor, but since you already have the 350 thats out. Definetly do headers, especially since its a truck and they'd be a breeze to install. Also definetly use the copper gaskets. I did long tube cheapee header on my '86 Silverado 305 and the difference was amazing.

Also a side note, Accel is complete junk, I learned this early. Use either Delco or Bosch for plugs and anything else for wires, coils, caps, and rotors. MSD and Mallory make some great wire sets.