Engine swap to an LT1

[bucket]

Your main goal here is a little better MPG and maybe some more power too, right? Just keep it simple and figure out what's bringing your mpg down, and just do a few upgrades that will really wake that 454 up. An 80's smogger 454 is a sleeping giant.

 

[Bagged Dually]

What are your suggestions on mods to the big block?? I've never had any experience with a BB. Every engine I've ever built or done anything to performance wise where all SBC and SBF. I know the BB is a whole different monster...or am I making it more complicated than it really is?? All my smog is now deleted, new long tube headers, new 02 sensor, and tune up so far. Still TBI

 

[bucket]

Treat it like it's a SBC, the basics are the same. A better intake and a mild cam will really help out in the power department. If it's in the budget, I highly recommend a roller cam with a timing set and cam retainer for a gen6 454. You would also get a cam meant for a gen6 motor. Beyond that, the TBI will be holding you back (custom PROM would be needed with a cam swap, Brian at TBI CHIPS is great to deal with).

Have you calculated your mileage since the tune-up?

 

[Bagged Dually]

No MPG calculation since the recent work. I'm still waiting to finish the exhaust. Right now it's just open headers. I'm going to try and finish it this week. Hopefully I can get it done and recalculate it.

 

[towjoe]

my 89 V3500 4x4 crewcab is in the 7,200 lbs range. It is a fully loaded silverado tho. I have a 2wd 86 C30 crewcab dually that is in the 6400 lb range last trip in to the scrapyard. I scrapped a complete 454 1978 crewcab dually ( it was on a contract job couldn't save it for parts damn it) and it was right at 6550 lbs.

 

[Joshua8336]

Been looking for a new power plant for the dually that will help out my mileage. I have looked into about every engine I could think of and didn't like something about every option I had looked into. Then today at work I started to wonder why not an LT1??
They seem to be everywhere cheap, they put out more HP and Torque than my TBI 454, get way better mileage, and the camaro weighed about 3,300 pounds stock. My truck only weighs a couple hundred pounds more and that should be gone with the big block out.
Can anyone for see any down side to using the LT1 in my truck??

opti spark is the only downside i can list. other than the previous comments about them not being a good truck motor as they don't have enough low end torque, and gain most of their power at mid-high range. but if you'll put some silicone around the opti spark you shouldn't have any issues.

 

[Tyger13us]

Been looking for a new power plant for the dually that will help out my mileage. I have looked into about every engine I could think of and didn't like something about every option I had looked into. Then today at work I started to wonder why not an LT1??
They seem to be everywhere cheap, they put out more HP and Torque than my TBI 454, get way better mileage, and the camaro weighed about 3,300 pounds stock. My truck only weighs a couple hundred pounds more and that should be gone with the big block out.
Can anyone for see any down side to using the LT1 in my truck??

My 78k10 short bed has a 1969 LT1,, it has all kinds of low end torque,, granted nothing like a BBC,, all depends on the cam profile ya use......

And about weight? on the scale front ground weight is 3200 lbs and rear is 2200 pounds with both 16 gallon tanks full......

th350/205 t-case.......

 

[foamypirate]

My 78k10 short bed has a 1969 LT1,, it has all kinds of low end torque,, granted nothing like a BBC,, all depends on the cam profile ya use......

And about weight? on the scale front ground weight is 3200 lbs and rear is 2200 pounds with both 16 gallon tanks full......

th350/205 t-case.......

Different LT1. We are talking GenII SBC with reverse flow cooling on the heads and a dizzy up front.

 

[Tyger13us]

Different LT1. We are talking GenII SBC with reverse flow cooling on the heads and a dizzy up front.

my bad,, didnt get the gen II part........

 

[woodsrider250]

I've wondered about this swap as well. The LT1 might not be a stump puller, but how much worse can it be than the turd of a 350 in my 74? How much would you notice in light duty use when coupled with stock 4.10 gear (in factory form my motor doesn't stay off-idle very long...It's in the midrange at cruise)? With highway gears my Dad's old LT1 Roadmaster Woodie got 28mpg before E10....It would hold a posi burnout at 1.5-2k.

 

[Jims86]

I've wondered about this swap as well. The LT1 might not be a stump puller, but how much worse can it be than the turd of a 350 in my 74? How much would you notice in light duty use when coupled with stock 4.10 gear (in factory form my motor doesn't stay off-idle very long...It's in the midrange at cruise)? With highway gears my Dad's old LT1 Roadmaster Woodie got 28mpg before E10....It would hold a posi burnout at 1.5-2k.

You would be better off installing vortec heads on your current 350.

 

[woodsrider250]

I'm likely going to pull/crate my motor and trans and install a 454. If I go budget/temporary I'd do exactly as you suggest. That was more of a what if on the LT1 from anyone who's tried it....specifically around fuel economy.

 

[Jims86]

I'm likely going to pull/crate my motor and trans and install a 454. If I go budget/temporary I'd do exactly as you suggest. That was more of a what if on the LT1 from anyone who's tried it....specifically around fuel economy.

Yeah, if anyone ever thinks of using an LT1 in a truck, I usually say vortec, because they came from the LT1 head design, except with regular SBC cooling passages. IMO, LT1 is to "Parts specific" to be used as an everyday hard working truck engine. Now, I would say different if the engine was in production in more vehicles, for a longer time period, and if the ignition system design was changed to a rear mount type dist, or even to coil packs...But The LS series has already been in production way longer, in multiple vehicle models, and as a result, would be a more cost effective swap. LT1 is just a vanity motor.

 

[woodsrider250]

I hear ya. The LS motors can be picked for the same $$$ as a LT depending on where you look....from trucks

Rough stab, how much on average does economy pick up from simply installing vortec heads/retrofit edelbrock?

 

[Jims86]

I hear ya. The LS motors can be picked for the same $$$ as a LT depending on where you look....from trucks

Rough stab, how much on average does economy pick up from simply installing vortec heads/retrofit edelbrock?

MAYBE 2-4mpg depending on how its driven, and if exhaust isnt monsterouse. The combustion chamber design is more efficient than previouse sbc heads, and the ports in the head are much taller.