literally.

car currently has a tbi 305 with a spun bearing. i want to completely ditch that engine, EVERYTHING. now i want to stick in a totally different 305 that is already carb'd and no i don't want to swap the tbi off onto the new engine i just want to stick with a plain jane carb. i know this has to be doable and i know this has to be very simple. i have to change out the gauges, right? that shouldnt be too hard should it? i mean i can always get by with just the oil, speed and gas gauges for a good while. i just want this to be done and over with. somebody help me out here.


the "new" 305 is from an 80's model chevy van. i have no idea what kind of main. what to do, what to do. thanks!!

 

No, you don't have to touch the gauges at all.

 

damn thats badass. great news. so whats the scoop? what all do i have to do? just pull the old junk engine out and stick the new one in, hook it up and fire it up then go?

 

Swap the switches and senders from the old engine onto the new one to keep the gauges working. You'll need a regulator to lower the fuel pressure from the TBI pump to a more carb-friendly level. The ignition wiring will change somewhat since you won't have computer-controlled timing anymore.

 

what do you mean by somewhat? what all do i need to do for it? is the regulator available at parts stores? how much do those run? i really want this done this weekend because i have no vehicle at all.


oh and i forgot to say THANK YOU!

 

Your current distributor has wiring to talk to the computer, the non-computer distributor that you'll need (and I'm assuming is coming with the other engine) will only need wires for power and the tach.

A common choice for the regulator is a Mallory 4309. You'll need a few plumbing bits to get it hooked up.

These questions are asked all the time, the search button should turn up all sorts of useful information.

 

sorry about not using the search button and i know it gets old answering the same questions a lot, but this really is the easiest and quickest way to get answers. but hey man, thanks a lot for the help. i had lost all hope haha til now, you just lit the fire back under my ***.


so overall this should be pretty much be a "1 + 1 = 2" type of deal?

 

More or less. If you've got an automatic transmission then you'll also need to provide some means of locking up the torque converter clutch. There are about a dozen ways to do it, try a search.

Your 91 305 will be a 1 piece rear main seal roller cam block. If you're getting an early 80s 305, it will be a 2 piece rear main seal non-roller cam block. You'll need a new flywheel or flexplate if that's the case.

Planning to do the whole job done in a weekend would be optimistic, especially if you've never done a swap before.

 

well its a 5 speed so i dont have the tq convertor to worry about and i wont be doing the swap alone. a couple buddies would be helping, both of which have pulled engines before. so i just need a new flywheel and a fp regulator? i'll search for a guide on the wire stuff for the distributor and see what i can come up with.


and it doesn't have to be done in 2 days really, just as long as i get the ball moving this weekend i'll be stoked.

 

Yes, possibly a new flywheel, depending on the age of your new engine.

I should add that if you have a mechanical fuel pump on the new engine, and it has a return line on it, you can use it in conjunction with the in-tank pump, and it will regulate the pressure for you.

Whatever you do, resist the temptation to start cutting "unused" wires just to "clean things up" when you ditch the TBI.

 

not even a problem, if it's cluttered i won't mind i'll just tuck them up or something.

so what, run the in tank pump into the mechanical pump and then use the return line on the mechanical pump to run to the engine?

 

The mechanical pump has an internal regulator that will vent excess pressure back to the tank through the return. The supply line from the in-tank pump will feed the inlet on the mechanical pump. The return line on the pump will connect to the return line back to the tank. The outlet of the mechanical pump will supply the carb.

This is actually how some factory carb setups were plumbed.

 

awesome man. thank you so, so much. you've been so much help

and hey, if i do start this project and i happen to run into any problems can i pm you for help?

 

Sure, but it would be better to make a public post. I do occasionally get away from the computer to work on my own cars.

 

not sure about around here, but most people just aren't as friendly and helpful as you are. :P

 

I'm as mean as anyone, you just got me on a good day.

 

well in any case, thanks again your help is much appreciated.