Seeking swap/rebuild wisdom

PlayingWithTBI said:

With the 4L60E, the EBL is out unless you run parallel computers. At least the Sniper and others have trans controls for more money - of course. You can get the hardware to tune and burn your own chips or, find a guy that will take you logs, tune, log, tune, and so forth. A mail order chip is the last resort, IMHO.

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That's good info....guess I'm glad to have a 91 with the 700r4. Once I decide (aka$$$) which way I go with the motor( LS is last resort) I think the EBL is the way I'm leaning.

Kenny302 said:

Thanks guys, good info. kinda backing up my own research. 4K for a bone stock motor seems pricey considering at 288k I will need to replace all supporting components. Atk had a stage 1 long block at a decent price but the reviews weren’t good. I’m afraid a rebuild will get a way from me. I like to make improvements and if the heads needed much work I’m sure I’d just buy aftermarket definitely would change cam nothing crazy, still need low end torque and want to run the stock converter or close to it at least. But if it’s goin to lead to after market efi and a separate trans controller that’s most the cost of an ls swap as I figured it 3500 bucks plus cost of engine and tune. I just keep going around in circles on this thing.

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Welcome to my brain!!!! Lol
So many ways to go.

I think I got really lucky with the TBI truck I built 20+ years ago. I used an early 70s 400 block, stock crank, 5.7" rods and KB pistons. Used stock rebuilt TBI heads, stock TBI everything. Used Flotech headers/Y-pipe, 3" single in/dual 2 1/2" out muffler n duals. I did nothing to the ECM, no chip, no tune, nothing. It ran beyond insane. It pulled like a freight train, awesome idle, good MPG if I remember. But the stock 700r4 didn't like the new found power after 235k miles. But the thing that made the biggest improvement (before the 406) was the headers. It was like I swapped to a big block.

Sounds like a little torque monster. I will definitely add headers when I replace the rotted flowmasters but I looked a few years ago for a 400 locally and could only find a few and they had huge bores. Used to have a race track down the road so a lot of that stuff got chewed up. No idea where I’d find a 400 block now days

Yeah, things have changed, unfortunately. Whether it's COVID or not, everybody's raised their prices. back in 2000 my new Mr Goodwrench long block was ~$1350, now you see what the GM Performance is. After all kinds of research and discussions, I'm probably going with a local machine shop for a complete rotating assy with flat top pistons for 10.1:1 compression. I already have the cam, aluminum heads, Edelbrock intake, and bored Throttle Body - it's still gonna cost ~$4380 But, it should last the rest of my life, my son can worry about it then, ha ha. YMMV

If it where mine and there is no ridge in the bores, I'd slap some fresh bearings and rings in it, and a cam and timing set.

Tbi is fine to work with for low to mid rpm. Stock computer is pretty simple as long as you just stick with VE table, and spark advance table. Only way to get the ve right after cam change is to data log it make adjustments, rinse and repeat. Goes a lot quicker if you have a wide band o2 and open loop. If you get a low rpm torquer cam, it should be fairly happy with stock tune and get better after fuel trims catch up to what the new cam wants. Jmho

Sounds like you are in a similar place as I was a few years back when I discovered low compression on the #2 cylinder of my 95 TBI. I went round and round and had parts lists and cost for several different options. I am going to share some of that logic and maybe it will help you.

Stock long block. Quick and effective. Would still have rebuild the throttle body and replaced any sensors that were original. Would not have given me the power bump I was looking for but TBI engines are relatively simple and if maintained very reliable. I also feel these engines do a little better in the low end torque area.

Upgraded 350. New heads/cam. Problem here is that the TBI management system is not forgiving to mods. You can get a tunable ECU or get the components to burn the chips. I figured if I was going to dive into tuning or modifying ECU parameters I would do it on a newer system. There are quite a few aftermarket self tuning throttle body systems, but there is extra cost associated with those.

96+ vortec system. Decent power boost over the TBI. Parts, harness, ECU sourced from junk yard or parts store. For the time and money there was more power to be had. I was not a fan of the spyder injector system and my 99 which has this engine has been a bit troublesome.

96+ Big block. Better injection system (IMO), Lots more toque which would have been good for the towing I was doing. Down side was it was going to be pricey and my gas mileage would have taken a hit. Everything would have been pretty straight forward in terms of a swap and I almost went this direction.

LS Swap. Most power gain (but not torque) Later fuel management system. I ultimately went this route. Cores were available and I rebuilt mine myself with outsourcing the machining. Wiring was time consuming. Tuning was not too bad. I could have bought an aftermarket harness and had the VATS and related turned off by a tuner but at the time I decided my time was better spent than the cash. Probably the only one more expensive than this was the big block. I had a good bit in buying new sensors, coils, headers, brackets, ect. I have realized a slight fuel mileage increase even when towing. I kept everything as stock as possible to minimize the ECU changes. If I had gone with a different cam and a custom tune I could have unlocked a lot more power. I still could. I disagree with the earlier comment on the reliability of an LS swap. If done properly there should not be any reliability issues.

Ultimately what I tell everyone is consider what you want to use the truck for and let that drive your decision. I was looking to gain some power when towing and hoping for a slight mileage increase when not. At the time it was easy to get an LS engine as well.

The fact that you have spare vehicles to drive helps. As you go down this list the time factor increases almost exponentially from a weekend job to a couple of months when you factor in learning wiring, tuning, and waiting on a machine shop.

By your original goals in the first post it sounds like just rebuilding your engine or getting a long block would be a good choice. If you start looking at head and cam upgrades it may be worth considering an LS swap.

Have you verified oil pressure with an external gauge or are you basing the perceived need for a rebuild off of the factory gauge?

1st-are you sure your oil pressure sensor is not bad? My 94 has good oil pressure but the sensor doesn't like to work when warmed up.
2nd-Jegs has a TBI long block for $2100, you might want to give them a call.

Thanks guys, never verified gauge but assume accurate as when she drops low enough the valve train gets noisy. Waiting on an autozone long block now but going to keep my core for later use.