BBC TBI or aftermarket EFI

[Rugger187]

I am contemplating a swap and am just trying to lay some groundwork and get some opinions and ideas.
I have an 89 GMC Jimmy with 1 tons and other mods that has a recently rebuilt 350. When I rebuilt it I also did all the TBI mods. It runs pretty good.
I also have a 78 2wd Blazer that has a 305 TPI and 700R4 combo out of an 87 Camaro.
I am also in possession of a really well built 454 that has never been fired up or installed in anything.
I was thinking of swapping the 350 into the blazer and getting rid of the 305. I would keep the TPI. I've already done my research on what this swap would entail.
I was going to drop the 454 into the Jimmy.
My question is about the fuel injection. Which would be the best way: scrounge the parts to make it a 454 TBI or just do an aftermarket EFI system like Accel or somebody?
Best way as in what would end up being the most reliable and be able to make the most power?
Thanks

 

[ryoken]

really well built 454 that has never been fired up or installed in anything.

you need to answer/explain this more thoroughly.. what's the cam?


you could run a modded stock setup, with maybe some bigger injectors and a chip.. or even megasquirt..

or dump the coin on something like FAST... a much simpler solution...

 

[Rugger187]

I will have to get the cam specs from my dad. He built the engine about 10 years ago to go in one of his projects. At the time I was building my 454 for my Bel Air and he said he went with a cam a bit smaller than mine.
Mine is a comp cams 11-242-3
Duration at .50 is I 224 E 230
Lobe lift of .3030/.3063 and separation of 110
I was looking into a FAST setup. Simple indeed.

 

[Rugger187]

I'll have to ask him specifics. I don't recall if his 'bit' meant one step smaller or a few.

 

[dyeager535]

Most reliable and best power being the criteria? TBI, hands down. I doubt reliability is up there, but if it's a concern, off the shelf parts are everywhere, you can go to an auto parts chain and say I need a coolant temp sensor from a 1989 K5, and they have it. Aftermarket most likely won't afford you anywhere near that level of accessibilty to parts.

Power isn't going to be significantly different with one or the other. It seems counter-intuitive I suppose, but the gains just weren't there when injection went from TBI to the Vortec CPFI, if you exclude the ~25HP normally attributed to Vortec heads over older versions. Sequential/coil on plug seems to add some control that can extract a bit more power, but IMO the cost vs. benefit isn't there for all that.

As mentioned though, anything other than bone stock you are going to want/need to re-tune the thing, and it's a lot more involved than some of the aftermarket stuff.

 

[paratrooper307]

An engine is a big air pump, power is mostly a function of how much air you can suck in, combust with fuel, and push out. On this type of engine, performance gains from one system to another are likely negligible. Having recently converted to a TBI system, the easy installation, solid performance, easy parts accessbility, and value make it a winner for me.

If you do go with a factory system, either learning how or finding someone good with tuning is key.

 

[ryoken]

yup, I've said it before, i'll say it again....

the cylinder boom doesn't care how it's fed, carb, injectors or fairies with a squirt gun...

what matters is the bumpstick, compression, manliness of the parts combo, yada, et al...


optimizing a TBI for a particular hotrodded engine can be tough... run "ok" is one thing, but getting peak performance will usually require some time and work.. data logging, multiple chip burns, bigger injector trials, etc may be required...

 

[blazer74]

fairies with a squirt gun...


That's a good one!