Tech question: What is the stock bore and
stroke of a 305 engine? Next, if the engine
is bored .30 over, what is the new bore dimensions? What about .60 over? Will boring out the 305 help unshroud the valves and increase performance?

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If I'm not mistaken, the measurements of a stock 305ci are:

bore= 3.736
stroke= 3.48

A bore oversize of .030 should end up 3.766.
A bore oversize of .060 should end up 3.796.

You may want to double check, though. Math wasn't my best subject in school.

I found a formula that you may like to use.

CID=BorexBorexStrokex.7854x#of cylinders

[This message has been edited by coach (edited June 12, 2001).]

 

reply to your last two questions.

No and No

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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver 15.26 @ 87.0
Reader's ride -> My Ride

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

The best thing you can do to that thing is to put better heads on it. Try something like 1.94x1.6 valves or if you can 2.02x1.6. Also gm makes some sweet vortec heads that drop right in place, using stock manifold and all. I am not sure if they were $400 a piece or $400 for both. Anyway, give this a shot, it is well worth it and the best thing for most heads for the 305's are 1.76x1.46 valves with tiny 58 cc combustion chambers. - My two cents.

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1987 Firebird Formula
305 LG-4
GM Vortec heads 2.02x1.6 valves
Crane CompuCam 2030
700-R4 Trans
4 barrel quadrajunk remained by holley (this carb stinks!!!)
edelbrock performer intake
Hypertech Thermomaster Chip
Open Element Air Filter
No Cat with Straight pipe (Dynomax muffler rusted apart and fell off probably could not stand the heat )
Accel H/P Coil

- Soon to be installed
383 stroker (built and ready)
NO MORE COMPUTER CRAP
700R4 Lockup kit
Edelbrock TES
True Dual exhaust or 4 inch single pipe to dual 2 1/4"
Stall convertor

 

Thanks guys. Anyone using the aluminum corvette heads on the 305 with TBI? Mine is a 1989 Formula, and it's tired...