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I just bought a fully restored 1977 gmc 1500. the body and interior are in great shape and the motor has a fairly recent rebuild. it has a 305 chevy small block and i am wondering what i can do to up the power in it and the price each upgrade will roughly cost. I would appreciate if you don't post about how the 305 is a waste of time and money and to buy a 350, i like the engine and am interested in adding power to the engine. So far i have looked at a stroker kit (making it a 335), new cams, vortec RSH 1.94 heads, edelbrock 650 carb, holley 300-36 intake, and cat back exhaust. will this be a good setup or should i add or lose anything to it. i am also looking at adding 3.73 rear gears to it. just wondering what someone with a little more knowledge thinks of this and also what cams would be a good choice. thanks
 

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Chevy small block 305

There is nothing wrong with a 305 engine. I have had several cars that had 305 engines. Check the casting number of your heads, I think it's the 4416 is the good ones. They will have to be ported. F-Bird'88 can give you some good advice of the work they will need. This summit cam would be a good cam to upgrade to. Summit Racing® Camshafts SUM-1103 - SummitRacing.com. Be sure to buy the kit that includes cam, lifters, and valve springs.
 

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305 Turbo-Fire 240hp
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If your already at 200hp then you should be happy. Get you a set of gears and then you wont be bothered by anymore engine upgrades cause youll be roasting the tires off your gmc. Get you a good free flowing exhaust system and your in the money.


I have a mild 305 with edelbrock performance cam(rv cam)and matching lifters, stock 601 heads, headers, true dual exhaust, 700r tranny, 342 gears. and im happy. Last dynoed at 240hp/230tq.:thumbup:
 

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thanks for the advice. I'm looking to make it into a high 200hp or maybe even a low 300 hp engine if possible without supercharging it. it has about 200hp right now
The 305/3-3/4" stroker crank deal was an invention to get the CA boys and their Camaros, etc. around the smog police more than anything. It'll increase the torque, though- but the cost is significantly more than what you need to spend to reach your goal of 250-300 hp. Put another way, I'd rather use a mini blower (that could be used on a 350 later) than I would a stroker crank.

An article w/some info/links: Chevy 305
 

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WFO
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According to Sam Weiss' flow sheets, the L30 305 Vortec head flow respectably even unported: 221 cfm int./163 cfm exh. @ 0.500" lift/28" water. Better than all but one professionally ported 416.

Needs springs/retainers, a Vortec intake, center bolt valve covers, and either self aligning rockers or adding screw-in studs and guide plates to use standard rockers.
 

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the motor has a fairly recent rebuild.
DING, DING, DING, DING. That's the alarm bells going off in my head. You have no idea of the measurements in the motor (block deck height, piston deck height, piston compression height, overbore, rings used, ring gaps, bearing clearances, chamber cc's, piston crown configuration, static compression ratio, etc., etc.), yet you are ready to throw parts at it and hope for the best????????????? DING, DING, DING, DING :spank:
 

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A 305 is not the best sbc to make loads of power. You can be thankful for 8 cylinders offering powerstrokes per rpm, and a 3.48 stroke to pull. Vortec heads , summit headers, a performer cam and intake with 3.73 gears , made a big difference from stock.

A cam is good , but if you are not sinking a ton into it, stay mild. Vortec 350 1.94int heads work good/cheap in a 305, just mill them to cc. The newer ls6 beehive spring and small retainer is a stable valvetrain for a performer cam.

A low profile supercharger will get you rethinking the 305 potential. Mucho bueno.
 

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spinn

A 305 is not the best sbc to make loads of power. You can be thankful for 8 cylinders offering powerstrokes per rpm, and a 3.48 stroke to pull. Vortec heads , summit headers, a performer cam and intake with 3.73 gears , made a big difference from stock.

A cam is good , but if you are not sinking a ton into it, stay mild. Vortec 350 1.94int heads work good/cheap in a 305, just mill them to cc. The newer ls6 beehive spring and small retainer is a stable valvetrain for a performer cam.

A low profile supercharger will get you rethinking the 305 potential. Mucho bueno.
spinn,might want to make a minor correction in your post,oops
 

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Nothing wrong with a 305. I have one out of 86 pickup in my 32 highboy. Its got a mild Competion Cam, roller rockers, Edelbrock performance intake with 600 carb, flowmasters with headers. Gets along way faster than I want to run. Here is video of what it sounds like

32 Ford - YouTube
 

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I just bought a fully restored 1977 gmc 1500. the body and interior are in great shape and the motor has a fairly recent rebuild. it has a 305 chevy small block and i am wondering what i can do to up the power in it and the price each upgrade will roughly cost. I would appreciate if you don't post about how the 305 is a waste of time and money and to buy a 350, i like the engine and am interested in adding power to the engine. So far i have looked at a stroker kit (making it a 335), new cams, vortec RSH 1.94 heads, edelbrock 650 carb, holley 300-36 intake, and cat back exhaust. will this be a good setup or should i add or lose anything to it. i am also looking at adding 3.73 rear gears to it. just wondering what someone with a little more knowledge thinks of this and also what cams would be a good choice. thanks
For the cost of stroking the 305 you can build a really great 350. Not that I'm opposed to 305s but on a cost to benefit basis it isn't worth doing this to the 305. You end up with 20 inches less engine, no weight benefit ala 347 vs 351 Ford, all for the same or more cost as a 350.

A stroker crank does not make more torque, the torque is simply a displacement function more equals more, less equals less; PERIOD! The only thing diddling the bore to storke relationship does within a fixed displacement is move the RPM around where the peak occurs, not the amount. Longer stroke lowers the max RPM where the peak occurs, shorter raises that point. For an otherwise idential configuration of parts that's all that's happening.

Bogie
 

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For the cost of stroking the 305 you can build a really great 350. Not that I'm opposed to 305s but on a cost to benefit basis it isn't worth doing this to the 305. You end up with 20 inches less engine, no weight benefit ala 347 vs 351 Ford, all for the same or more cost as a 350.

A stroker crank does not make more torque, the torque is simply a displacement function more equals more, less equals less; PERIOD! The only thing diddling the bore to storke relationship does within a fixed displacement is move the RPM around where the peak occurs, not the amount. Longer stroke lowers the max RPM where the peak occurs, shorter raises that point. For an otherwise idential configuration of parts that's all that's happening.

Bogie
The torque number might be a little higher in a identical engine size comparison.

Your point is alright for me. The 3.73 gear can be got cheap online.
 
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