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nwofarrier06 12-31-2012 01:08 AM

305 build ?
hello, my name is robert
I had some ? on a sbc build im been wanting to do. this is what i was thinking so far. and yes i know that I would be better off with a lot of other engines but I'm just wanting to build a 305

bore/stroke - 3.766/3.75 in
rod length - 5.7 in
combustion chamber vol - 68 cc
deck clearance - 0.010
Piston Head Volume cc - +10.00 cc
compressed head gasket vol - 0.030
4 bolt conversion with a girdle
high vol/high presser oil pump
195 cc intake runners/ 80 cc exhaust runners
dose what i have sound about right?

thanks for you time :cool:

nwofarrier06 12-31-2012 03:33 AM

9 1/2 on the compression sound about right to you? would you know what cam would match up well with that or how I would go about doing the math to find the correct cam?

nwofarrier06 12-31-2012 02:36 PM

light duty 78 c10 and ill be running 105 in it all on the strip maybe on the street now and then just to show it off the trans will bee a th350 from monster i haven't pick gears for it yet and the rear is a gm 12 bolt 3.73:1 locker not sure on the trucks wight yet but ill let you know when i'm done with the rear end

I was also think of maybe going with a low compression build with a set of turbos?

thanks for the help man.

American Muscle 01-01-2013 12:26 AM

i was thinking of putting a 142 on my 305. Is it just a bolt on, tune and go sort of deal or do i need to go inside and do some work

vinniekq2 01-01-2013 03:39 AM

a 305 with a 3.75 stroke? 335? are you looking for high torque with moderate HP? what heads are you using with 195 cc runners that fit a 305/335?
what is the performance target ?

1Gary 01-01-2013 11:09 AM


Originally Posted by F-BIRD'88 (Post 1629156)
Instead of spending all the money on the stroker crank and block girdle huge heads etc.
That will need a ton of RPM parts and need to rev to the moon.
Why not use the stock block and crank and supercharge it. You need raw torque and power to get that heavy truck going. low cr 305 with a weiand 142 blower+750 holley/edelbrock. 400+++HP on pump gas.
stock low compression 305 short block.
ported stock heads, ported vortec heads, .....ported 083 head
ported camel back head) (1.94x 1.50)
ported 113 corvette l-98 aluminum or equal or a better aluminum head.

big power at moderate boost on pump gas. bigger power on race gasor water injection wiith agressive 10-14psi boost from a weiand 142 blown 305. Big visuals on your truck.
twice the power and torque gain for the money spent.
1/4 the complexity and hassle.
305 blown with a larger 177 weiand is another path. Even more power and visuals.
Nothing grabs the eye like a Roots Supercharger. Turns as small CID motor into a much larger motor.

$$$$$$$$$$$$$$$$$$$$$ cause

1Gary 01-01-2013 11:40 AM


Originally Posted by nwofarrier06 (Post 1629140)
light duty 78 c10 and ill be running 105 in it all on the strip maybe on the street now and then just to show it off the trans will bee a th350 from monster i haven't pick gears for it yet and the rear is a gm 12 bolt 3.73:1 locker not sure on the trucks wight yet but ill let you know when i'm done with the rear end

I was also think of maybe going with a low compression build with a set of turbos?

thanks for the help man.

Do you have the welding equipment and fabrication skills for a turbo set-up??. Not sure about a twin turbo,there are a whole host of good turbos in pick and pull yards for not much money.Your right,there has been a history of guys who have used turbos on 305's.Relative success to the size of the engine.
I suggest you hold off a rear end gear ratios until you have firmed up your game plan.

FYI: The blower option is neither cheap or easy. A simple quick search shows some pricing for it and when looking at that remember you need to buy all the parts to make it a turn key.

weiand superchargers | Price comparison and reviews at

Oh and you don't just increase the boost at will on them without a consideration for the internal parts of the engine.

Of all the power adders,the turbos are the easiest on a engine.

1Gary 01-01-2013 03:58 PM

If you check out the supplied links:

MSD 6-BTM CD Ignitions 6462 -

From $2600 to 2900 for the kit with more parts yet to buy

A easy $500 for a MSD and ignition parts

And we haven't even bought a 750 Holley or mod'ed for a blower

Still haven't bought a cam and kit

Still haven't bought headers and exhaust

Still haven't bought acceptable heads and done the machine work

A easy $5000 to $6000 that as you said is trail and error that if a mistake is made you then have $6000 invested setting in the shop in pcs.

That pixs with a blurred head shot...........................well

I think if I have to hand hold these blower advises given so a more accurate cost factor is posted,maybe it is you that should spent more time on the porch.

The turbo's can be had for next to nothing.And do not cost anything in the loss of power to drive them as a belt driven blowers do.

vinniekq2 01-01-2013 04:01 PM

ya,someone do a turbo board for comparison.Im reading up on boosted engines and I would love to rob the parts yards for power adders

1Gary 01-01-2013 04:09 PM

I forgot to add in the costs of a fuel pump and system.

Vinnie-check out the power adder section.

1Gary 01-01-2013 08:57 PM

Kind of hard to debate the pricing found on the net.

I'm not wasting anymore of my time.Never said anything about it being complex.

vinniekq2 01-05-2013 06:53 AM

Done a little math. Blower will add 30% more power(plus or minus). I chose a lower number because I am going to do this as cheap as possible. I start with a "free" junk yard 305. These things might make 150 hp.
Ill round up to 200 HP. I buy a blower cam from summit$99.00,I buy the rest of the cam kit another 200. Buy a gasket kit and timing chain 150.Now I tackle the heads,again going el cheapo.I buy a porting tool and porting kit,250. After spending 40 hours porting my heads I go to the machine shop and get a valve grind, 150 machine shop time. I buy a used intake 100, a used carb and rebuild kit 150. I look around and find a used ignition with timing retard 200. I buy a cheap blower 2200.I will add in 500 more to adapt the blower,maybe replace the hood. other misc items,like plumb oil line etc to blower,different brackets and pulleys,,,,
looks like I now have a 200 HP engine that now make 260 hp?I super tune the engine and make 310 maybe 330HP? all for less than 4k
The engine was free(or cheap). It will last ????until I break it

Thats is 1500 bucks cheaper than buying a brand new 415 HP roller cam 350 turn key engine with 2 year warranty that also has dart shp heads

1Gary 01-05-2013 09:14 AM

Don't think Vinnie I am inclined to put that kind of money into a 305 or advise anyone else to do that.Then run it until it blows up because the engine was free,but all the other stuff wasn't doesn't sound logical.There are tons of articles in the fan based car magazines just like the advise given by F-Bird relevancy to real street in doubt.

BuzzLOL 01-07-2013 04:15 AM

.. The 335" engine the OP spec'd out in first posting looks like about 400HP by 6000 RPMs with a 219/229 - 225/235 range cam... about 9.5:1 compression ratio with 10cc dish pistons, good quench, 68cc chamber 195cc port heads, and the 3.75" stroke...

.. Not sure what quality 3.75" stroke crank he is talking, but keep RPMs down if a stock 400 or other cast crank... not sure what parts he already has, if any... looks to be a fun bracket/street truck...

.. In another vein, Car Craft website has budget ~$1,000, mid-priced ~$5,000, and pricey turbo builds articles... using kits available online/eBay...

spinn 01-07-2013 01:57 PM

Supercharging is inexpensive. You can get a used bm 144 for under 1000. I got one and rebuilt it, knocking in new bearings. It worked perfect and had everything needed. A pulley swap makes huge power changes. 15 psi is double the hp. You do not need a big cam. A small cam like the 1102-1103 will make a huge difference.

My 305 C10 has the eforce unit, chosen to work with the vortec heads. Some pics in journal.

The BTM was $50 off from msd, over the end of the summer.

A edelbrock 110 gp mechanical fuel pump was $75.

The cold mornings have been no problem. MPG is the same. Road manners are awesome.

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