Right now i have a 1985 firebird coupe. Its 305 with a 4bbl on it, the thing is the 305 is on its last leg and it doesnt produce alot of horse power. I want to replace the 305 with an engine that will offer more horse power, money isnt a huge issue but if were talking 1000$ for an extra 10 horses then ill take a pass. I was thinking taking out the 305 and buyin a 350 and boring it out to a 383 and putting in the stroker kit. I hear this is one of the best ways to achieve alot more horsepower at a reasonable price. Well the thing is this is going to be my first engine build and i do not know if i should hunt down a used 350 from a truck or another vechical or if i should buy a crate motor. I have been reading though i am wondering about the ls1 i understand that its an engine with a different firing pattern, but wat makes it so great that i hear about it all the time. So all input on my thread is appreciated, and i want to keep the car carbed.

also is it true that if i regestier the car with classic tags that it would not have to get emmissions done on it thanks

 

You can't bore a 350 out far enough to make it a 383. About as far as you can go is .060", which makes it about 360 CID (although still a 350). However, it makes ALOT more sense to bore it AS LITTLE AS POSSIBLE while still cleaning up any wear and also reaching a diameter for which you can readily buy pistons; which would be .030", which results in your 350 having about 355 CID.

To get to a 383, you bore your 350 block .030", and use a crank with the stroke of a 400 which is 3.75" instead of the 267/305/350 stroke of 3.48".

For a first engine build, I'd strongly recommend keeping it simple; which would be, a 350, in whatever overbore is necessary. Since the core, i.e. the wore-out thing you're going to rebuild, is the CHEEEEEEEEEPEST part of the whole project, I'd recommend getting THE BEST POSSIBLE one; which means, avoid the 70s blocks, and look for one that can accomodate a roller cam. The all-around best choice would be a COMPLETE but worn-out and not useable in its present state 96-2000 truck engine, because it not only will have the roller stuff, but also the highly sought-after (for good reason) Vortec heads.

I have never understood the whole "crate" thing. It really doesn't make any difference to the outcome whether you buy a junk motor and rebuild it, or buy a junk motor that's already been rebuilt and is now in a "crate", if the same parts and machine work are done to both. The advantage of building your own is that YOU get to choose exactly where your money goes, and YOU control the process; those are also 2 of the disadvantages, if you're inexperienced and can't make good choices because you simply don't know what they are yet. The advantages of a "crate" motor are that someone with more experience makes those choices; and, since they're not having to account for your individual pieces individually but instead are running a large number of them through identical processes, the cost can be lower and the results more consistent; and, especially for a first-timer, the cost of enough tools to do a good job is MORE THAN the cost of the motor, meaning, your first motor will cost MORE THAN DOUBLE the cost of an otherwise-identical second one.

Personally I build my own.

 

so your saying that i should scratch the idea of the 383 and stick with a 350 from a truck in the early 00's. Whats so good about the vortec heads, in the newer 350s, My goal HP is atleast 300, i dont think its unrealistic for my first engine build. Also i could just change out the manifold on the truck 350 and put in a manifold that execpts carbs right? correct me if i am wrong please

 

Yes, basically that's it.

Power comes from the ability to move LOTS of fuel and air through the engine. That's what those heads have going for them: the best-flowing intake ports ever on a stock GM SBC head. They leave all the "legendary" muscle-car heads completely in the dust.

Find one of those motors, in a junkyard that has lots of trucks. Look for construction co. trucks with LOTS of miles on them. A motor like that will be cheap because nobody in his right mind will pay "ready to install" prices for it; all it's good for, is to rebuild. But that way you'll already have the best possible core, including all the little goodies you'd otherwise have to go out and buy separately.

Yes there are carb intakes available to fit those heads.

 

300hp is pretty easy to get - easily obtained from a 1970's 350. The stock 350 from most 1970's cars was rated at 290hp - better intake and headers/exhaust will bust 300hp even with the junk smog 1970's heads. I have an old 350 with the junk 882 heads and if it's rated at 290hp, I'm easily over 300hp, but not far over.

If your seriously interested in a 383, PM me. Our local car club president just received a 383 shortblock for about $1700 shipped, and I can get you the name of the place (in TX) he ordered from. It seems to be a stout motor. Of course that doesn't include heads, cam, intake, distributor, oil pan, but good heads and the rest can be had for under $2k easily. That makes a total of about $3500 invested for about 375hp. In contrast, my neighbor just ordered a ZZ4 crate motor - $4950 for 355hp ... $1500 more for 25 less horses just because it came preassembled in a pretty box.

I just bought the neighbor's old 350 (nothing wrong but the cam ate a lifter) - another 1970's 350 with 290 stock hp. I'm now researching/thinking about how I can build it up. I have folks trying to talk me into making it a 383, but I'm with Sofa here, hate to do that to an old block when it works so much better on a newer block. But I'm hoping decent cam and heads will get me there.

{I kinda want to rub it in the neighbor's face - and take his old motor that he swears has major problems, and get more hp out of it than the 355hp that his $5k ZZ4 is making, all for under $2k}

Good luck with your choices. Make it a learning experience, but don't tackle a major build on the first go - I'd say snag a 350 from anywhere, build it decently while learning along the way, install and have 10 times the fun you ever had with the 305, and look towards a bigger more complicated "next build" in a few years.

 

thanks for all the input anything i should know if i want to make the 350 with the vortec heads carb based? wat carb i should buy, if i need to change anything with the engine to make it work. I also i have a 4 speed trans in it, not sure what kind tbh dont no awhole lot about trans

 

Bump

 

You can keep the carb and dist you have now, and get an Edelbrok Performer intake.

If you go with the Vortec truck motor, either get a used LT1 cam from a camro/Firebird or Corvette, NOT an Impala or Roadmaster; or, a moderate aftermarket one such as a Comp "502" grind http://www.summitracing.com/parts/CCA-08-502-8/ If you go with the aftermarket cam, you'll get AHELLUVALOT more power; but more machine work will be required on the heads, and you'll have to use better vavle springs. You'll have to replace the springs no matter what, but for the better cam, just stock replacement ones won't cut it. So the best choice as usual comes down to the intended use and goals for the car as a whole, and the budget.

Your transmission is a 700-R4.

The "classic tags" thing depends on what state you're in. SOme states allow that; some place mileage restrictions on using the car, or forbid you to drive it at night; just the ability to hack off the emissions (which basically don't cost any power in that setup anyway) isn't worth some of the hassles that come with the "classic" tags. Most likely it's not a good idea.

 

i was thinking using a speed demon carb because my stock carb has been giving me alot of problems

 

Would the patriot performance "vortec style" heads be able to handle that cam? spring wise anyhow?

 

Before you buy one of those carbs, CALL THE FACTORY and see what they have to say. Their help in selecting the right carb will be critical.