I don't know jack about the L69, but trying to get 150 or so whp up to 400 whp is going to be a long shot. I don't see it being possible without some sort of power adder. No idea how well they hold up to being pushed that far either.

If an LS1 is on the table, I would also keep in mind other gen 3 & 4 engines as there are other LS options that could get you to your power goal either more easily or cheaper.

 

Thank you kindly for the response and the suggestions. I will take a look into the other LS motors but it seems the LS1 are a bit more available by me. I was contemplating eventually adding forced induction to the build.

 

I agree with Bumpin96monte getting a extra 150hp out of a 305 is going to be tough without spending a ton of money. Obviously you could make a generation 1 350 or 400 to make that kind of power and that would probably be the easiest route as it would be just drop the engine and your done. I have never swapped from a Gen 1 to a LS engine, but going that route you will be getting into a new wire harness for the engine, installing a different fuel delivery system, new exhaust, engine mounts, spacer for the old trans to mate the crankshaft,or if you swap to a newer trans you will have to modify the firewall if I remember right. You could throw a different intake and a carb at the LS and save some wiring hassle A lot depends on how much you want to spend and if you can do all the install yourself if not shop labor rates are in the budget, I imagine the Gen 1 route would be the cheapest way out unless you could find one already done. Good luck

 

I was planning on swaping the transmission out for a 4L80e. I am planning on doing most of the mechanical work myself but best laid plans as they say. I am currently just in the planning stage and gathering all my information so I have time to save up money. I am stil on the fence about going to fuel injection or convert the motor to carburator.

 

 

I'm honestly suprised to hear that. The number of truck / SUV 5.3s and 6.0s far outpaced the number of true LS1s built, so you'd figure it would be a ton easier to get one of those.

That's exactly what I would do in a car like this. Would definitely simplify the swap.

Unless you're planning on pushing power a lot further than 400 whp, I wouldnt bother with a 4l80. A well built 60/65 will handle that with ease with a lot less weight and drivetrain loss.

 

I am tinkering with the idea of forced induction which is why i was thinking the 4L80. this way if i have that factored into the cost but dont go that route I wind of with some extra cash. I was talking to a buddy of mine and I think I will probably go with the LQ4. having looked further into that they are all over the place. Guess i didnt look as hard as i thought.

I liked my carb when I had it but am trying to decide which roue is best for this. Other than the wiring what else is there involved with staying EFI?

 

You'll need to add the stuff that goes into the wiring - O2 sensor, MAF, PCM, etc. You'll also need a high pressure fuel setup - either a traditional feed / regulator / return or an aftermarket returnless in tank setup. Depending what else you do, youll either need to tune it, have someone tune it, or buy and aftermarket 'auto tune' pcm.

That's the nice thing with the carb setup. You'll have to spend a little more in hard parts, but you drop on the intake, carb, and something to control timing (like an MSD 6LS), and you're ready to rock.

Don't get me wrong, I'm 100% an EFI guy. Running a full setup gives you a lot more fine tuning ability in timing and fueling. But, at 400 whp, you're not really shooting for the moon, you don't really need tons of adjustability for a setup like that.