I have a 305 and want to put a carb on it. What must I do? Mechanical fuel pump? New intake? New heads? What all is involved in this?

 

Why? The TBI is a nice setup. Heads are good, you do not have to go with a mechanical fuel pump but you need to get the pressure down ans rewire it since it goes thru the computer system. Intake carb and ignition system.

The computer controls the ignision system an if you are pulling the EFI then you are all the stuff for the ignition system. Which would mean you need an old vacuum advance setup. Expect to loose about 10% of your HP.

 

The reason why is because I want to change the heads,intake, and put a bigger carb. The car has catback three inch magnaflow on it. My first mile stone before this TBI to carb swap is to put tubular k member, + tubular lower control arms, new springs, struts, and convert the rest of the exaughst to 3" cateletic converter, and larger headers.

 

O and also a cam of coarse

 

If I do the mods while keeping the TBI I'm thinking it's not going to be able to spray enough fuel to keep up with the cam/heads .....

 

how many miles are on the ENGINE (not the car)?

Do you plan on yanking it when you do all that? If not, why not?

Let's see, you'll have the intake, heads and cam out so the lifters and pushrods are out.

you're purchasing new heads so here comes new springs etc with it. You'll be buying new lifters and pushrods as supporting items for the new cam and springs/rockers

soooooo, why invest all of that time and money and not get the short block rebuilt?

And next, I'm going to say what needs to be said

Why invest all of that time and money on performance upgrades when they will also fit on a 45 cid larger block? You are obviously looking for performance.................

 

Well I am looking for performence, I also want to keep the 5.0 for originality purposes. Just wanted to pep it up a little. She has the t-5 tranny and don't want to go too extreme on the power for fear of blowing the tranny to bits. I suppose you are right about just building one outside the car and then swapping the motors out, then that leaves me with a spare motor. Lol, which isn't a totally bad thing.... In the end though I will still need to know what's going on as far as how to supply gas to my new Demond carbed motor.

 

I originally bought the car to put a 383 stroker in it, but did some researching and not alot of z28 5 speeds where made that year, so I decided to restore her with some upgrades. But if I ever did blow the tranny a six speed will be slapped in and then I can get extream with how much torque I can get out of a 305!

 

You do not want to build a 305 unless your goal is to build a fast 305. If your goal is to build a fast car then pull the 305/T5 and put them in storage. I have put a lot of crank kits in these 305s bone stock under warranty. I doubt they have gotten better with age. When I ask the engineer at the GM training center why we had issue with the 305 but not the L98 350 he said it all came back to the rigidity of the 305 block. The design was made to support better fuel mileage and it was lightened as much as possible. Even if you put good part in there once the block start to flex it is very hard to predict what is going to happen. You can find guys that have 325 HP 305’s but for every one you find I’ll bet you can find 25 people that blew their 305 at or right before the 300 HP mark. Once you blow the original 305 so it is not repairable there goes any chance of the “rare” car being valuable.

 

As long as you go into it with that outlook, you'll be ok. You can pep it up a little, but don't expect to make it a street terror. "There's no replacement for displacement" isn't an ego thing, it's practicality. To get 300 hp out of a 305, if that's ever your goal, will be pushing the engine's limits very hard. Getting 300 hp out of a 350 is easy, and the engine is still "loafing" to achieve that.