Warmed Over 305...What Do You Think About Trying?

[alextreme76]

I figure this topic has been brought up plenty of times, but what does everyone think about warming over a 305? 

Clearly an unloved engine, my faith was restored in my 83 305 after reading this http://www.goingfaster.com/spo/carcraft325hp305.html

I figure Edlebrock EGR intake, cleaned up carb, and headers with exhaust will be plenty of power for me for the time being if i can really make about 220hp with it, but I really would like a cam and other go-fast goodies in the future.

[red4wd]

I went through this back in the late 80's with my 305.  I put a 260 Comp Cam, a performer intake, a 600 holley double pumper...it wasn't impressive at all.  So my next step was to build a 350 with a 268 comp cam and and use the intake and carb.  The setup in the 350 made plenty of power...as many Mustangs, IROCs and Monte Carlo SS found out. 

[alextreme76]

hmmm...i would just rather play with the 305 since its already in there and its somewhat unique.

i figure if i can get some 4.10s and if i can really make 220hp with those cheap and few bolts on and 300hp with heads that would be plenty.

i would rather blow up the 305 with nitrous than do a run of the mill 350

[VileZambonie]

There's nothing unique about a 305. Most pepole just don't like throwing money into a toilet and flushing it down.  If you are heck bent on keeping your 305 then just throw a cam, intake and headers on it but don't waste your money on heads.

[Stewart G Griffin]

i think it's a wonderful idea;  You have to remember that the 85-88 Monte carlo SS's ran Mid 15's all day without even trying with a bone stock 305.

I'm not sure what your emmsion laws are like, but i would do first is to get headers, then true, full dual exhaust.  An X crossover does not nessesarily make more power than a I-crossover pipe.  I will research more and report back later.  You also want to go to at least a 3"pipe, i think?  I've got flowmasters (series 40 i think) and i've got no complaints.  Although it's a tad too loud if you go to work early in the morning.
I would also suggest exhaust cut-outs.  Electrically controlled if possible.

The 305 has the same stroke as the 350 so i don't feel that you are as handicapped as alot of people might think.

I'm not sure if the vortec heads will work with the 305's bore size.  If they do, that would be an easy and cheap way to go fast.

As far as intake, i can't help now because i have to sort out my own mess.  I think holleys fuel injection would help, but is it worth the $1000 it will take to install it?   IR manifold with 4 weber carbs would probably be the ultimate for a carbureted system but it would cost much more than $1000.

Upping the compression and a camshaft change will really wake things up, but i'm not sure what cam would be the one;  I think the numbers end in 929 or something.  This is a chevy part #.

More later.......

[F-body Demon]

To finish some stuff for the guy up above me here. Vortec Heads will fit on a 305. But lemme search really fast for a link to a 11 second tbi 305; no kidding.

[F-body Demon]

Okay I cant find it. But check out www.thirdgen.org its got tons of 305 info. And that post IS in there I just cant risk getting fired trying to look for it any more . laterz

[75stepside454]

dollar for dollar, obviously a 350 is cheaper. But sometimes cheaper isnt as much fun. I built a mild 305 a few years back I put in a 86 El Camino that ran 13.20 with 3.08 gears.  I used KB143 pistons that made just shy of 10.0:1 compression . I used L-98 aluminum Corvette heads I found at a swap meet. a mild Compcams XE256 hyd.flat tappet cam, Performer intake, Holley 570 cfm carb, a D.U.I. H.E.I. distributer. ran great, pulled good vacuum. I was surprised at how crappy the MPG was.anyway it was fun.

[Stewart G Griffin]

So the corvette heads will work with the 305's bore size?  That's awesome.

Running 13's on the motor is pretty good.  The 86 elco has got to weigh at least 3300-3500 lbs. in stock form.

[SUX2BU99]

Wow, that sounds really mild for low 13s in that size of car! Even low 14s would be impressive with that combo.

[jo3y1nf4nt3]

i actually messed with my 305 (+.030) and never got it to run.  i had purchased a cam (crane #100172), some 1.6 roller tip summit rockers, some dished hyper. pistons, and of course the lifters and springs.  i already had the edelbrock performer intake, the 1406 holley carb, hooker headers, i pocket ported the heads myself and polished them (again, myself).  actually, the first time i did get it to run only lasted about 300 miles.  i adjusted the rockers per a small block engine builders book(start at tdc and work in *90 increments) and well, somehow i shaved the lobe on the cam, not sure which number right now.  so i took the motor back out and they sent me a new cam.  well, in between replacing it, i left the house (and the wife) and when she had the truck delivered to me (with new dents, broken windshield, busted mirrors, bent grille, hood damage) and the motor(full of dirt and mud) turned upside down in the bed of my truck, i never got a chance to mess with it...i lost motivation for the  time being. 

anyways, when i get the truck repaired, i'm going with the blueprint 383 they have in summit magazine...405hp and 445 lb/ft.  along with a 700r4. 

so, if anyone wants some parts for a slightly modded 305 (minus the destroyed carb) lemme know! 

[Mr79C10]

WOW,, that just made me rethink about the 305. I have the chance on a  V8 given to me. My girl's dad has 1 sitting on a stand in the garage. So not knowing what it really was I ran the casting # and found its a 305 from 1969. Last report was that it was running when pulled. Now I'm rethinking of taking it and swapping out my 6banger, cuz I would REALLY LOVE a auto trans.!!!

[jo3y1nf4nt3]

[Stewart G Griffin]

Pls re-check the casting #  (or post it here) because i don't think 305's came out until '76.

I'm quickly becoming the "small small block" (anything 305CID and under) guru here because i'm into that stuff----small CID displacements from a SBC.

[Captkaos]

because i don't think 305's came out until '76.

You are correct, they started in 1976 (replacing the 262).