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I have 252,000 miles on my 88 Caprice with a 305 and it has never been apart. Uses about 1/2 pint of oil @ a 3000 mile change interval. Runs great and gets good MPG on trips too. This is not my first high mile 305 either. Not a high HP engine but very dependable. :blowtiedb:

-Bruce
 

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I have a 305 in my daily driver 96 pickup, 225,000. I'd still drive it anywhere!
 

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Good 305?

The bore in this engine is small. If you intend a performance rebuid later I'd look for a 307 rather thana 305. WE raced sprint cars with 307 blocks back in the day.:bowtier:
 

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I have a 305 in my daily driver 96 pickup, 225,000. I'd still drive it anywhere!
Same here.....Got around the same mileage on my 98 Silverado....I can be going 80 with the OD and not even realize it....Purrs like a kitten and gets around 20 MPG on the highway.:)
 

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Definitely not a performance engine. I have one in my '57 and it is sick. I am building a early 60's 327 to take its place.....Bill
 

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These engines were born when GM was struggling to meet emissions requirements. Coupled with a 2.56 axle, the long stroke (good torque), small displacement 305 fit the bill fairly well. Slow turning, decent gas mileage, plentiful & cheap parts, but not a good base for a performance engine because the intake valve size is limited by the small cylinder bore.

One of the guys over on CT has the TBI (or TPI?) version in a full-size van and gets >20 mpg. I wouldn't mind having one of those in my 69 pickup.:tu

Maybe someone will jump in here and tell us about the 300+ HP 305s used in some road racing classes, but those things have some serious (and expensive) head work, and are probably relieved at the top of the cylinder bore to un-shroud a larger intake valve.
 

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You need to qualify or expand what you mean by "good"
305's are dependable motors , and will respond within reason to the usual
performance upgrades such as a good intake manifold, headers/exhaust and cam changes. The heads are a choke point and will limit what you can do with simple bolt ons. The 305 HO heads being the best of the stock 305 heads.

You can put on heads with 1.94" intake/1.5" exhaust valves but typically 350 heads have a 64 or larger cc chamber and thats too much as the 305 heads are around 55 cc so you have to mill the heads to get the c/r back up.
People have reported good results with milled 350 vortec heads on them.
If you have a tight budget and have a good 305 on hand theres no reason to not use it as most bolt on performance parts can be later moved to a larger sbc when your budget permits.

Regards, Robert
 

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You need to qualify or expand what you mean by "good"
305's are dependable motors , and will respond within reason to the usual
performance upgrades such as a good intake manifold, headers/exhaust and cam changes. The heads are a choke point and will limit what you can do with simple bolt ons. The 305 HO heads being the best of the stock 305 heads.

You can put on heads with 1.94" intake/1.5" exhaust valves but typically 350 heads have a 64 or larger cc chamber and thats too much as the 305 heads are around 55 cc so you have to mill the heads to get the c/r back up.
People have reported good results with milled 350 vortec heads on them.
If you have a tight budget and have a good 305 on hand theres no reason to not use it as most bolt on performance parts can be later moved to a larger sbc when your budget permits.

Regards, Robert
The perfect answer
 

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I have several 305's.They are good engines within their design range.
They were never intended as performance engines where h.p. is needed.
My 82,305 made it to 190,000.
My wife's 88 Caprice is still going pretty good.Got it over 100 mph one night(going to the hospital)Carbed 305/700-R4.Very high miles.
89 G-30 van with 305,tbi-great mileage-don't know the miles,but a lot!
82,3/4 ton,305/400,still going.
They supposedly have a bad reputation,but most of it is B.S.
Mike.:bowtieb::)
 
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