what would be cheaper and more benifitial.....305 lg4 with a 262 cam or how much would a used 350 cost from a junkyard....just kinda wondering because i plan on doing one of the two this spring but just am not sure on prices for the 350....for cam,lifters,springs,retainers,valve seals,gaskets and various tools and stuff it would be just over $400...i like to do things right the first time ...which is why i want a 350..but once again am not sure on price.....BTW the 400 thing in my profile....just for kicks...you wouldnt believe the responses from some people :lala:

 

basically you can build a 350 for the same price as a 305. one thing to keep in mind is: more cubic inches=more horse power

 

well should i build up a 305 or how much would a used 350 cost..so basiclly....305 with cam intake and headers and holley 650 or 350 with intake headers and 650...

 

Let's assume the 305 shortblock is in good condition and the 350 needs to be rebuilt. In this specific example, you can get more power for the dollars out of the 305 than the 350, up to the point where the 305 power is maxed out. Then, without doubt, the 350 will take over.

The first step, regardless of which way you go, is to get rid of the LG4 exhaust, from the exhaust ports at the heads to the rear bumper. Trash it all. Get headers and TPI-style y-pipe, cat, and cat-back.

Now, a warning - spending money on a carb like Holley is a waste of money, performance wise. You can support a lot more power than a streetable 305 can produce, and the same is basically true of a 350. Keep the LG4 carb, do some simple tuning (rods & hanger), and again, ditch that LG4 air cleaner and get or fabricate a dual snorkel air cleaner. Upgrades to the stock distributor, coil and module, is a good idea for performance.

Now, about your 305. It's a decent performance motor if you do the right things to it. The cam has to go, you're already talking about that. Get a computer compatible version, you'll be amazed at the performance it can produce. You need valve springs to match the cam.

But, you need to improve the heads. Either do a self-porting job on your LG4 heads, or get the World 305 heads and have them pocket ported (at a minimum). There has been a big discussion on the Tech forum about the relative benefits of those choices, check it out and decide for yourself.

What is the origin of your 305? If '85-later 3rd gen, that's good. It's got flat-top pistons for good compression. If something else with dished pistons, not so good, but don't bother putting new pistons in.

A junkyard 350 will need all of the above mentioned supporting cast - exhaust, air cleaner, cam, ignition, and head work. Add a shortblock rebuild to that, you've exceeded the $'s/HP that a 305 build-up will cost you. But, it will make more power, and have more potential for growth futher down the road.

 

thanks that helped out a lil bit...i allready have headers and exhaust...no cat.....i have a edelbrock performer intake....a holley 600 4150....yehh its the crappy one.....i got a open air cleaner 3 inches tall with drop base....i got a 1" carb spacer....and a pre 85 lg4...now my 305 has a good 90,000 on it most likely...i was thinking about an XE262 for cam....maybe a lil porting too but i wouldnt take off too much "meat" because i wouldnt want to mess anything up

but now if i got a used 350 it would be used....but so is my 305....id just throw all the stuff above minus cam in it...and ill allways have money later when i get a job...yes i dont have a job yet...lil less thank 1 grand left in the bank form paper route....but with a 350 id be better off for future mods...and also according to what your saying there wouldnt be much of a difference in compression either because both have dished pistons...

now i plan on doing this all once the snow dissapears prolly late march....then after that its getting a paintjob for my b-day present...the 2 step macco...the best one they have....then thatll bring me up to my 16th b-day in may....i just want to find the most reliable/cheapest/most cost effective way....if i have to pay a few hundred more for a 350 but be better off later...that would be under cost effective....but no $750 heads yet...

 

A 305 usually will cost slightly more to build than a 350. The gaskets and pistons are just a bit more expensive because they are less popular, less used, less demanded, whatever you want to term it. Its not enough to offset the cost of the 350, but there is a slight difference.

I would do a cam swap if I were you, or do nothing and save the cash for a 350 thats been rebuilt and all. Finding a good used engine can be difficult, and its sort of a crap shoot.