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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
So I've built a few 350's and one 383 over the years, and I've always managed to fall into one or another through friends or acquaintances and have never actually had to buy one new, or have one machined. That being said, for a cruiser, TPI replacement, or a fun street car for the day, you could buy a longblock for well under $3000. I remember the 4 bolt main L31 "R" Vortec 350 was under $2500 for the longest time. Now there's not too many GM options for "replacement" engines, and they're pretty pricey. I think that L31 is now close to $5000 for a long block. Finding a good machine shop is getting harder and harder, if you can even find one to build you something.
Might be looking to build something soon. LS engines are great, no argument, but with a 6th gen in the garage, building the biggest and baddest isn't on my list. A TPI or old school orange and black carbed 350 carries more appeal to me. Curious what you guys are doing for SBC builds these days.
I've seen all those different players before, but they're ALL a LOT higher than they ever used to be. That's life in 2024 I guess!!!! That L31 is $4900!!! OUCH.
Jegs sells a a rebuilt L31 through ATK for a touch over $2500.
That's interesting. Might look at that. Not that the L31 is the only game in town, but I always felt it was a great 4 bolt main, 1 pc rms with quality parts for any decent build. Even if you ditch the heads, the remaining shortblock was still a decent foundation for the money. Heck, keep the heads and just swap the cam. Anyhow with prices where they're at now, if it's not built exactly how you need it, it's not worth it. $2500 ain't bad though. Might look at that.
That being said, ATK and BP both had some decent 300 to 400 hp complete engines.
I like this one but it's not exactly what our OP is looking for. Full of good parts and it's ON SALE! But if you read the fine print there are a few caveats that would exclude it from your typical replacement 350.
I right at $1000 on this 400 small block build. Stock rods, pistons, bore. Prepped block and turned crank, rings, bearings, cam, DLC lifters. Figure the heads will make the power and take some real money for those.
I appreciate the feedback guys. Tom, building myself looks like not a bad option. -and there are still cores out there. Fast 355 mentioned Smedding, and I saw an affordable 383 shortblock at various states of assembly for good prices. Read up on them too and generally seem to have good feedback. I've built transmissions, rear ends and engines from a shortblock. Maybe it's time I assemble the whole thing. I dunno, we'll see. Prices make it tough when you can buy a whole running and driving LS 4th gen for less than $5000, BUT....really don't wanna go LS.
. Fast 355 mentioned Smedding, and I saw an affordable 383 shortblock at various states of assembly for good prices. Read up on them too and generally seem to have good feedback.
A member here @raptere just purchased a Smeding 383 shortblock. I've had great deal of dialogue with raptere and the feedback regarding Smeding is generally positive.
Through a little modest insight on my part and his communications with the supplier he was able to affect a few changes (namely pistons) and have resulted in what I think is going to be a very satisfying result. Perhaps he'll chime in.
I appreciate the feedback guys. Tom, building myself looks like not a bad option. -and there are still cores out there. Fast 355 mentioned Smedding, and I saw an affordable 383 shortblock at various states of assembly for good prices. Read up on them too and generally seem to have good feedback. I've built transmissions, rear ends and engines from a shortblock. Maybe it's time I assemble the whole thing. I dunno, we'll see. Prices make it tough when you can buy a whole running and driving LS 4th gen for less than $5000, BUT....really don't wanna go LS.
I farmed out some machine work and rotating assembly balancing for the 383 but I built both my 383 and 350 in the past 5 years from the bare block up. The 350 was done with no machine work at all from a ~120K mile L31 that came out of a 2005 Silverado. I put a low mileage LT1 rotating assembly into it from a LT1 that had become a 395. The bores in that L31 were in such good shape I did not even hone them. It runs strong, quiet mechanically, perfectly even compression in all 8, very little leak down, and carries great oil pressure. Compared to the horror stories of reman engines of late, I will take it. I took the used roller lifters apart, cleaned them and put them back together even giving the plethora of lifter issues from new lifters as well. Literally the $1200 Proflow 4 setup was 2x what I have in that ~400 hp L31 350 longblock.
Thanks for the reply, I'll read up on that. A 383 certainly has it's appeal!
....I had reached out to a local machine shop earlier in the week, and actually heard back right after I posted earlier this afternoon. I'd had some trouble finding someone who really seemed to WANT my business, but this guy was recommended and he was more than willing to talk shop. He said he had a few high mile L31 engines. He'd dis-assemble, do the necessary refresh machine work and let me re-assemble for about $1500, including the purchase of the engine, which he already has. He said he wouldn't know the full scope until he got into it, but he also mentioned he's seen many L31's that didn't need much at all, and could probably get me out the door cheaper. Not having to FIND and transport the motor makes it easier too. I've never assembled a short block before, but it doesn't seem any more complicated than a transmission, so I'm game. Love to do it at least ONCE in my hot rodding career lol!
Thanks for the reply, I'll read up on that. A 383 certainly has it's appeal!
....I had reached out to a local machine shop earlier in the week, and actually heard back right after I posted earlier this afternoon. I'd had some trouble finding someone who really seemed to WANT my business, but this guy was recommended and he was more than willing to talk shop. He said he had a few high mile L31 engines. He'd dis-assemble, do the necessary refresh machine work and let me re-assemble for about $1500, including the purchase of the engine, which he already has. He said he wouldn't know the full scope until he got into it, but he also mentioned he's seen many L31's that didn't need much at all, and could probably get me out the door cheaper. Not having to FIND and transport the motor makes it easier too. I've never assembled a short block before, but it doesn't seem any more complicated than a transmission, so I'm game. Love to do it at least ONCE in my hot rodding career lol!
If you've someone that appears eager and is willing to build a spec on the core in hand then I'd be on that. I did exactly this and while I appreciate the convenience and compactness of having a "crate" engine delivered, something about having a hand in parts included was a deal maker for me.
I paid $500 for a used L98. Had the machine shop bore it over 30 and turn the crank for $375. Wound up buying a reman set of 217s later and rebuild kit with hypereuctectic flat tops,. Re-used #049 cam and stock lifters. Im all in for about $1750ish and am more than happy I went that route. Had fun putting it together with my Dad and my son
Thanks for the reply, I'll read up on that. A 383 certainly has it's appeal!
....I had reached out to a local machine shop earlier in the week, and actually heard back right after I posted earlier this afternoon. I'd had some trouble finding someone who really seemed to WANT my business, but this guy was recommended and he was more than willing to talk shop. He said he had a few high mile L31 engines. He'd dis-assemble, do the necessary refresh machine work and let me re-assemble for about $1500, including the purchase of the engine, which he already has. He said he wouldn't know the full scope until he got into it, but he also mentioned he's seen many L31's that didn't need much at all, and could probably get me out the door cheaper. Not having to FIND and transport the motor makes it easier too. I've never assembled a short block before, but it doesn't seem any more complicated than a transmission, so I'm game. Love to do it at least ONCE in my hot rodding career lol!
The L31 method has been my suggestion for going on 20 years now. Even did a writeup back in the day on the TBI board that has been a sticky for years. Even back then I was seeing 200-300K mile trucks with engines that looked practically new when they were opened up if they were well cared for. Recently my buddy had one in his 1998 K1500 work truck that had something like 470+K hard miles on it. He built another used L31 that was in very good shape and swapped it into his truck. He sold the olde engine to a local guy that ended up having it honed and put it back together as a 377. He was going to get it bored but the machine shop said it did not need to be and would be in useable condition with a hone. Literally with all those miles it did not even need to be bored. No ring ridge, no out of round bores and no appreciable taper with 470,000+ miles on it. It had multiple rings that were physically stuck to the old pistons with carbon buildup which explained the blowby it had, some sludge from a prior owners laxed oil change schedule and the cam bearings were in rough shape, but it still ran decently and carried decent hot idle oil pressure. The 377 is going into a mid 80s K10. He recently shared a video clip with my buddy who then shared it with me of his old 350 turned 377 running on a run-in stand. Sounded great for being essentially a stock L31 with a 3.75" stroke crank, 6" rods, new Icon forged pistons, a GM 6492 cam, a dual plane, 650 cfm carb and headers.
Fast, I'm gonna have to check out that thread. Don't spend much time on the TBI board, but I'm looking forward to reading. I've been of a fan of the L31 for awhile, but never had my hands on one. I think I'm gonna get the ball rolling after the new year. I admit the idea of building it from a bare block is certainly growing on me!
