Author Topic: 305 and 350  (Read 6396 times)

Offline murraygmc

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305 and 350
« on: April 06, 2009, 06:37:48 am »
what is the difrence betwene a 350 and a 305..???
85 gmc high serria 4x4

Offline zieg85

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Re: 305 and 350
« Reply #1 on: April 06, 2009, 06:51:58 am »
The internals are slightly different in bore and stroke.  Physically they are the same in size. 
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline 78 Chevyrado

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Re: 305 and 350
« Reply #2 on: April 06, 2009, 11:47:25 am »
305 has a smaller bore than a 350, but the stroke and everything else except the heads are the same.  The heads are different because the bore is smaller.
Kenny

1978 C-20, 350/400, 3.73, Graystone Metallic, Raceline Renegade 8 Wheels - 18x8.5, 275/70R18 BFG KO's

Offline murraygmc

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Re: 305 and 350
« Reply #3 on: April 06, 2009, 02:05:56 pm »
i bought this motor in good fath it was a 350 and iv bought a lot of parts 4 it turns out its a 305 when i put it in i had the whole dog house and core suport off go it put all back togather and then i found out it was a 305 stuped me didnt check the numbers till i got it all put back togather so now i have a 77-76 305 with a 2 barrel rodchester  what is the differance in horse and just plane power from a 350 4 barrel ?
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Offline eventhorizon66

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Re: 305 and 350
« Reply #4 on: April 06, 2009, 03:12:11 pm »
If you want a reliable cruiser, 305s are OK.  But if you bought it to hot rod someday or need something for towing right now, get rid of it and find a 350.  The difference is about 40 lb-ft of torque @ 2000 rpm between a stock 305 and a stock 350.  Peak horsepower figures don't mean jack squat for a daily transport work truck.
« Last Edit: April 06, 2009, 03:18:48 pm by eventhorizon66 »
'85 C10 SWB 350 700R4 TKO600

Offline murraygmc

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Re: 305 and 350
« Reply #5 on: April 06, 2009, 03:44:43 pm »
o ok than i might keep it untill i get readt 4 my 4in lift and 33 12.50 s   thanks alot
85 gmc high serria 4x4

Offline Russ130

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Re: 305 and 350
« Reply #6 on: April 06, 2009, 05:29:50 pm »
The internals are slightly different in bore and stroke.  Physically they are the same in size. 

Hmmm, and how is the stroke different?

The heads can only go up to 1.94 intake valves due to the smaller bore. However you can really wake up a 305 with 58cc combustion chambers and 1.94 intake valves. That with flat tops and a good cam will work very nicely.

Offline zieg85

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Re: 305 and 350
« Reply #7 on: April 06, 2009, 06:28:46 pm »
The internals are slightly different in bore and stroke.  Physically they are the same in size. 

Hmmm, and how is the stroke different?

The heads can only go up to 1.94 intake valves due to the smaller bore. However you can really wake up a 305 with 58cc combustion chambers and 1.94 intake valves. That with flat tops and a good cam will work very nicely.

I was mistaken on the stroke as 78 Chevyrado pointed out.
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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