Rant.

I had a '96 Silverado (L31/5 speed) for 15 years that I ran the WEE out of...put 220k miles on top of the 80 it had when I bought it...towed my boat all over carnation through the rocky mountains, to Maine and back, Tahoe....the truck got WORKED...but WORKED right back. A friend of mine started calling it, "The Kenworth". I sold it at 300k miles, still ran like new. AWESOME truck. awesome engine. Sold it in 2017. Shouldn't have done that.

Have had a few trucks since then, didn't love 'em. bought a '98, same truck, but w/the L30 and a 5 speed. "Yeah, it's down 25 horse to the 5.7, but it'll go alright, and it's a 5 speed"...so I bought it. I've had it for about 4 years now? And here is my review of the L30: What a f'n PILE. It's had zero *****, zero. No f'n ***** at all. The thing is totally gutless turd. But for that lack of power, at least you get the reward of....terrible gas mileage! That's right! 12-13 towing the boat (old truck did 14+ every trip) 16 around town (18-19 old 5.7), and 17ish hwy (L31 did 20+). Well, well...well.....I know, I know, it's no "hot rod", and it probably has to "'work too hard" in that truck....but at least it's reliable! ....right!? It's got about 150k and today my kid was drivng from here back to his place w/it. Spun a rod bearing. What a WHIMP. I've had 305's that lasted forever....but not this'n. This engine is like that kid at school who sucked at everything, D's and F's....sucked at sports, had no social skills at all, scared the girls away and on top of that, wasn't even a nice kid........that's this 305. A total f'n pathetic, ****-box, LOSER, POS of an engine from day 1, until it left us today....mercifully. As a terrible parent might say; "L30!?.....I wish you were never born!"

Rant off.

 

Now is the perfect time to swap a GM HT383E create engine into it.

 

400.

 

Something I agree with. Grab a Holley 21-152 timing cover while you are at it because the plastic covers do not seal to the older blocks well at all.

 

. Good tip. Thanks.

I was going to reach out to you at some point (after I find a 400), and ask you about injector and tuning options. There is a 37k mile 400 in a Vandura motor home near here that I may chase down....

 

Actually have a buddy that scored one of those too. Probably the most common engine GM put into those Class C van based RVs from 75-80.

AUS has higher flowing spider options based off the MPFI upgrade spider. That being said based on the cost of that spider, I would probably come up with some other SBC MPFI manifold if you do not need to retain EGR. Stockish 400 will likely not need a higher flow spider especially if it is a short rod engine and you do not plant to rev it.

As for tuning, what is your emissions situation? I would upgrade to a DBC P59 myself. I have a DBC P59 calibration for a L31/5spd in a 2005 GMT800 that would be a lot better starting point than the L31 Van 0411 tune due to the manual transmission from the factory. The only software that can be commercially bought to tune a 96-97 Black Box is JET DST and their support of it kind of sucks, TBH. I use HP Tuners or even open source on the P01/P59s.

 

Well since you mentioned it I have 2 Ram Jet 350 induction systems and I only need 1 of them. No provisions for EGR and takes a Vortec throttle body, IAC and TPS. The 24lbs LT1 fuel injectors are on the outside of the intake manifold like they should be.

 

Thanks Airwolfe, I'll keep that in mind. Like to keep it mostly stock/stock acting.

If an L30 is a POS "Vortec" 305, and an L31 is a Vortec 350...what is a 400 CID "Vortec"? Will I have an L32 here, soon? Grandpa truck....here comes 6.6L of FUNK! GET READY! Going to Pick 'n Pull tomorrow to git me some heads.

 

A Honda 4-cylinder with a turbo can make 300HP+. A Caterpillar 3408 was rated for 250HP out of the box in the '80s.

There were good reasons OTR tractors used the Cat engine instead of the Honda for pulling 80,000 pounds over the hills. Apply that to your "305/350" musings.

 

L31'd LF6?

ProbablY 15 years ago now, I put together a 406 TBI that had been rebuilt with stock style ~22cc dished pistons that kept the 5.565" rods for a friend for his 1995 G30 cutaway class C RV. Used a Comp 252H cam, the stock 810 swirl ports that had a little porting and 2.02/1.60s in them, stock intake, stock TBI unit with 454 injectors and stock exhaust manifolds on it. I did some tuning on it. It was paired to the stock 4L80E and 4.56 gears. That 406 pulled the ~12K RV + 5K boat like it had 2 of the stock low compression 1-ton 350 TBIs in it. The same hill that had the 350 in 2nd gear screaming its guts out at 50-55 mph that 406 went up at 65-70 mph in overdrive. A mild 400 is a torquey SOB. If a 305 TBI was a L03, a 350 TBI a L05, I guess the 400 would be a L07, lol.

If you want a nice tame cruiser out of that 400, I would probably use a MTC1 cam or Crower Baja beast. The cam may seem small but it is still 10* more duration at 0.050 than the GM 929 cam or 13* more than the 1264 Vortec cam.

https://crower.com/camshafts/beast-cams/chevy-262-400-baja-beast-hydraulic-camshaft.html

 

Appreciate the advice and cam suggestion....I ended up not doing this. I don't like that truck (in case you couldn't tell! ), and I found a clean, 70k mile 5.7/5 speed, truck that I think that I WILL like, and bought that, and that will be the truck that I care about.

For the Grandpa truck, I went the cheapest route I could find, to make it sellable; a $500.00 Vortec 350 from someone's back yard.






One "bonus" is that the turd L30 did have the updated injectors in it....so those went onto the 350. The 350 had the older poppet style injectors in it, still. Problems.




Safety first! I can't believe these crap ching-chong-china come-alongs are rated at 4k lbs. NFW....thing seems questionable at 550 lbs.





That engine is installed and running now (drove it to work today). A surprise from this swap (for me) was how decent the drivability is with 45 more cubes, more head, with zero tuning at all. Bolt in and drive it. Especially w/the 5 speed, I thought it might feel surge-y, or laggy, but it actually runs pretty good. Definitely more tq'y and pulls the mountains here way better than turd-ville L30 did. Good enough that if it didn't have crank windows (combined with a fancy OH console and center console)...if it didn't have a 12 bolt.....if it had 3.73 gears instead of 3.55's or something dumb like that...if it wasn't wrecked with retarded options, I might actually want to keep it. But I don't, so it'll be going down the road w/it's 500 buck, 350.

 

Dude. You're hilarious. Thanks for the laughs. All true. And that highschool kid you described? That's probably 90% of us. Lol. And judging by the rants on YouTube by all the pissed off mechanics out there, the auto engineers are all in a full steam ahead competition for the Darwin Award. They're taking "planned obsolescence" to a whole new level. Really thinking the Amish have it right. Hang in there brother.