Can someone set me straight 305 to 350

[BigBlocksRule]

Hey, ozkiwi, see if any of your mates are interested in a 350 block that belongs in Australia. I've been tearing 350's down for years and this is the first of this oddity that I've ever seen - the casting number is upside down - has to be read from the engine side rather than the tranny side.
A casting for down under!!!
Ain't gonna be cheap, though - I've never heard of another like it.

[ozkiwi]

All I have got to say about that is "thank god for gravity".

[BigBlocksRule]

Originally Posted by Metalshapes

I'm sure I will catch some grief for this but what the hell here goes. I'm not sure where and why 305s have gotten such a bad wrap, they are great little engines and can be made to perform very well, some one wanting to go from a 305 to a 350 for the extra torque is absurd. Both engines share the same crank they will interchange as will the rods, torque is based on stroke and the only way to increase torque is to increase stroke this is why the 383 is so popular. I would never swap just to have a 350, my truck currently has a 334 in it, (A 400 crank in the 305 block.) the small bore allows for some impressive mileage figures, while having the ability to out run most 355s.

Torque is increased by stroke, but also by BORE. The small bore of the 305 restricts valve size which restricts flow. Three different engines - one short stroke, big bore, one medium stroke and bore and one long stroke, small bore, all 3 make the same power, period. You either have expanding gasses pushing against a larger piston face or it pushes for longer with the longer stroke, both are the same torque.
305's get a bad rap because they're a POS from a performance standpoint. They may make decent street engines but hot rodders avoid 'em for the same reason - a similarly built 350 will wax it's a$$ thanks to the larger bore!!

[ozkiwi]

I have decided to stop mucking around and just buy a motor and get the F$%^
on with it .It is going to be a crate motor I will take my chances and I am going to buy this Part# GM12486041-1
and buy a suitable intake to mount my quadrajet.I am going to cool it with this set up from leadfoot racing AE716-716FS-14
and use all my other bits if they are not too stuffed.
I need advice /opinions on and intake and a set of headers to suit this motor.It looks really tight in there on the passengers side so if anyone has a photo of their set up in this truck can you post.

[ozkiwi]

Will the LE9 305 exhaust manifolds bolt up to my 330HP HO Vortec heads???
Keep reading conflicting information.
I cannot change to headers until after the truck is registered and the motor is going in before that.

[mrolds88]

I ha an 86 a while back (RCLB K10) 305 4 speed. Mechanical fuel pump, 4 barrel, old style perimeter valve cover bolts. Basically it was a new style block and old style top end. Ran good enough. I could squeak 15.5 MPG out of it and it would move my 10k trailer, not well, but I could do what I needed to do.

[Desert1957]

Here is a list of parts you might need with that motor.

GM PERFORMANCE 350 HO 12486041

http://skillmanracingparts.com/Merch...1/12486041.jpg


Our lowest priced performance crate engine, the 330 horsepower 350 HO doesn't sacrifice power or durability, it just pumps up the value. With its 4-bolt main block, nodular iron crankshaft, forged steel connecting rods and light but strong cast aluminum pistons, this engine screams durability. Add to the strong foundation a pair of 64cc Vortec cast iron cylinder heads and a dual pattern camshaft with just a bit of a "lumpy" idle, and you've got the muscle car small block that you've been looking for. Dressed to impress with chrome valve covers and front timing cover, this engine will look great between the fenders of your favorite street rod, muscle car or grass roots racer. The cylinder heads on this great little performer use 1.94" intake and 1.50" exhaust valves that are sprung with 1999 corvette L31 valve springs. The 64cc chambers yield a healthy, yet streetable 9.1 to 1 compression ratio. The cam is a modern dual pattern interpretation of the old '65 to '67 corvette 327 cam. But with more lift and duration on the exhaust side, it does a better job of clearing exhaust from the combustion chamber. We also decreased the duration and lift ever so slightly on the intake side to build more cylinder pressure. The result is a cam that makes great torque and horsepower with the 350 HO's 9.1 to 1 compression ratio. Add the new dual plane intake manifold GM# 12366573, 600-650 cfm carburetor, HEI distributor, balancer, water pump and exhaust manifold or a pair of headers and you have an outstanding muscle motor with a broad, smooth torque curve and an honest 330 horsepower. This manifold has four bolts, not six, to attach it to the cylinder head. Older six-bolt manifolds will not fit the new Vortec heads. The 350 HO is not intended for marine use, and should only be used in 1973 and earlier pre-emissions street vehicles or any year off road vehicles. Technical Notes: Engine ID code is CC. Requires a counterweighted flywheel or flexplate, (GM Part#'s 10105832, 14088646, 14088650, 14088765, or 14088767). Requires either a 6.75" (GM# 6272221) or 8" (GM#12551947) harmonic balancer. Oil dipstick located on right side (passenger's). 650 cfm carb recommended. Chrome valve cover's and timing cover included. Intake manifold, distributor, flywheel, harmonic balancer, water pump, and exhaust manifolds are not included.

Desert

[BigBlocksRule]

Too bad shipping is so much - I have a 350 block with the casting numbers UPSIDE DOWN. It's the only one I've ever seen and I've handled hundreds. I think it belongs down under...

[silvereagle07]

Originally Posted by ozkiwi

Will the LE9 305 exhaust manifolds bolt up to my 330HP HO Vortec heads???
Keep reading conflicting information.
I cannot change to headers until after the truck is registered and the motor is going in before that.

They should. I have the same style heads on my truck but with chevelle midlength headers and haven't had any issues. Great little engine. But when you get it. I would remove the oil pan and make sure the oil pump is tight. Just sayin. I have had two GMPP crate engines with them loose. I just replaced the last one with a melling oil pump because the pickup was loose. I could have braised it but I wanted a new pump. Great street engine.

[Slonaker]

I have done the crate 350 conversion on my '86 using the 260 hp #10067353. PM me if you have questions about what has to be swapped.

Slonaker
Posted via Mobile Device

[chevblood]

ozkiwi, update bro?

[ozkiwi]

Originally Posted by chevblood

ozkiwi, update bro?

Ended up with a motor that does not exist as a crate part number????
But they sell plenty of them here in Australia.
Has exactly the same specs as a 330HP HO but with a roller cam.It is a roller cam for sure not the flat tappet cam listed for an HO ??
Put a alloy performer inlet manifold on it mounted my stock quadrajet and a set of summit racing ceramic long tube headers.
Whatever it makes at the rear wheels it's more than enough and makes the old tired 305 feel like it was about 80hp.
Only Had 2 problems with it so far. The header heats the starter motor up after a long run it struggles to turn over so will fit a heat shield of some kind and the new radiator is too good at it's job and the motor runs cold with the 160 thermostat that was in there for the old 305 and stock radiator. I will change it to a 180 Asap.Other wise very happy.

Very pleased I did not get the 260hp crate engine even though it would have been more than good enough.

[walka]

Just buy a engine from eagle and stop messing around
Posted via Mobile Device

[PAWS 72]

Originally Posted by Metalshapes

I'm sure I will catch some grief for this but what the hell here goes. I'm not sure where and why 305s have gotten such a bad wrap, they are great little engines and can be made to perform very well, some one wanting to go from a 305 to a 350 for the extra torque is absurd. Both engines share the same crank they will interchange as will the rods, torque is based on stroke and the only way to increase torque is to increase stroke this is why the 383 is so popular. I would never swap just to have a 350, my truck currently has a 334 in it, (A 400 crank in the 305 block.) the small bore allows for some impressive mileage figures, while having the ability to out run most 355s.

I just had to get that out, it is all in what you want to do and the funds allowed, I have a little over 400 dollars in this engine and it has done well by me, thought I would stand up for the 305.

Glad someone stood up for the 305's. I bought this truck with a 305 that came from Autozone and it is a peppy little feller with better oil pressure than the 350 I had built for my 72. If I can get some one to adjust my carb like it needs to be I think I will have a pretty good engine in the 86.

Gotta get some updated pics.This is when I bought it.

[Jeepwm69]

Originally Posted by ozkiwi

Have seen a couple of local guys but fast thinking of doing it myself and put the extra money into the motor as they want what seems like pretty serious money.
Pm me your number and I will give you a call.

Can you tell what size wheels and tires you're running, and whether that truck has been lowered any? I really like the stance on that truck, and mine is bone stock. If yours is dropped any, how much and how was it done?

Beautiful truck. Seriously.

[ozkiwi]

Originally Posted by Jeepwm69

Can you tell what size wheels and tires you're running, and whether that truck has been lowered any? I really like the stance on that truck, and mine is bone stock. If yours is dropped any, how much and how was it done?

Beautiful truck. Seriously.

Thanks.
Wheel size (15 inch) and ride height are stock.

[Jeepwm69]

Originally Posted by ozkiwi

Thanks.
Wheel size (15 inch) and ride height are stock.

What size tires are you running?

[JCampbell]

Originally Posted by Metalshapes

I'm sure I will catch some grief for this but what the hell here goes. I'm not sure where and why 305s have gotten such a bad wrap, they are great little engines and can be made to perform very well, some one wanting to go from a 305 to a 350 for the extra torque is absurd.

Yeah, you will.

I guess I'm a moron, cause I dig my 305. They're great little street engines, so long as you don't have a bunch of unrealistic expectations for them.

Dual plane Eddy intake, 416 "HO" heads, mild cam, full exhaust...been told that combo runs about 220-230 HP, which is enough to smoke the tires and still get 20-22 MPG w/ a 700R and 3.08s. Good enough for my daily driver. Yeah, you'll get more power out of a similarly built 350, but you won't get anywhere close to the same fuel mileage. And what do you really need for a daily driven street truck? 300+ HP ~or~ decent fuel mileage?

Here's one more for ya: I'm in the middle of a TBI conversion right now, too. I must really be a moron...a 305 AND TBI.

Different strokes for different folks. If it's a toy, by all means, go w/ a 5.7+ and build the hell out of it, but for a daily, I'll take a mild 5.0 every day of the week.

[mrolds88]

305's have a place. That truck I spoke about had the 4bbl 305, manual 4 speed (1:1 high gear) and 3.08's with 31/11.50/15's. Even here in the mountains, if careful, I could get 15.5 mpg. I did wind up pulling the 305 when I found it needed a freeze plug. It was one of the ones behind the motor mount. Since I was going to have to pull it to put in that freeze plug and I needed to pull that trailer, I swapped in the 350 that I had. Bottom line is that each of us need to find an engine that works well withing the parameter of our expectations.

[ozkiwi]

Originally Posted by Jeepwm69

What size tires are you running?

235/60 on front and 275/60 rear

[ozkiwi]

Originally Posted by JCampbell

Yeah, you will.

I guess I'm a moron, cause I dig my 305. They're great little street engines, so long as you don't have a bunch of unrealistic expectations for them.

Dual plane Eddy intake, 416 "HO" heads, mild cam, full exhaust...been told that combo runs about 220-230 HP, which is enough to smoke the tires and still get 20-22 MPG w/ a 700R and 3.08s. Good enough for my daily driver. Yeah, you'll get more power out of a similarly built 350, but you won't get anywhere close to the same fuel mileage. And what do you really need for a daily driven street truck? 300+ HP ~or~ decent fuel mileage?

Here's one more for ya: I'm in the middle of a TBI conversion right now, too. I must really be a moron...a 305 AND TBI.

Different strokes for different folks. If it's a toy, by all means, go w/ a 5.7+ and build the hell out of it, but for a daily, I'll take a mild 5.0 every day of the week.

My truck is running the same carb on the 350 as the 305 untouched.The carb does not know it's sitting on a 350 now and at any given throttle setting controlled by my left foot it is delivering the same amount of fuel as before.
I now have to press it down a whole lot less to get the equal amount of drive or get a lot more torque for the same amount of fuel.I have no doubt the new motor with it's vortec heads will be more economical driven at the same pace as the 305.Naturally having more torque and hp will be too tempting a lot of the time and I will burn more gas because of that.
Finally if the 305 had not been tired I would have happily kept running it but it was crazy to rebuild it when it would have cost more than the crate I have in there now.

[JCampbell]

I apologize if my post sounded like I was dogging you for going with a 350. It wasn't. It was more of a response to the general dismissal of the 305 without taking into consideration it's strong points.

However;

Originally Posted by ozkiwi

My truck is running the same carb on the 350 as the 305 untouched.The carb does not know it's sitting on a 350 now and at any given throttle setting controlled by my left foot it is delivering the same amount of fuel as before.

While it may be true that your carb might not "know" what engine it's installed on, the bigger bores on that 350 are going to require more volume, and your carb will deliver based on vacuum demand. By the vary nature of how a carb functions; more volume=more air, more air=more fuel.

Simple as that.

...Not that I'm trying to sway you; I just wanted to point that out.

[ozkiwi]

Originally Posted by JCampbell

I apologize if my post sounded like I was dogging you for going with a 350. It wasn't. It was more of a response to the general dismissal of the 305 without taking into consideration it's strong points.

However;



While it may be true that your carb might not "know" what engine it's installed on, the bigger bores on that 350 are going to require more volume, and your carb will deliver based on vacuum demand. By the vary nature of how a carb functions; more volume=more air, more air=more fuel.

Simple as that.

...Not that I'm trying to sway you; I just wanted to point that out.

100% right how convenient that I forgot those bigger pistons are sucking harder
Anyway all the factors that come into play that effect economy 305 verses 350 are beyond my understanding and have no meaning until I stop mashing the gas pedal to the floor.But certainly measured fuel consumption has not increased when both motors are compared when driven for economy .

[Rich84]

[QUOTE=JCampbell;6153463]Yeah, you will.

I guess I'm a moron, cause I dig my 305. They're great little street engines, so long as you don't have a bunch of unrealistic expectations for them.

Dual plane Eddy intake, 416 "HO" heads, mild cam, full exhaust...been told that combo runs about 220-230 HP, which is enough to smoke the tires and still get 20-22 MPG w/ a 700R and 3.08s. Good enough for my daily driver. Yeah, you'll get more power out of a similarly built 350, but you won't get anywhere close to the same fuel mileage. And what do you really need for a daily driven street truck? 300+ HP ~or~ decent fuel mileage?

Here's one more for ya: I'm in the middle of a TBI conversion right now, too. I must really be a moron...a 305 AND TBI. QUOTE]

My setup is about the same as yours (same heads with rv cam)..With TPI. It's a lot of fun to drive and still gets around 20 mpg with 3.73s.

[JCampbell]

Nice!