Gm performance 305 block

Rich Biebel · 10-06-2015, 12:31 PM

The 305's came out when GM was going to change everything to the Metric system....but never really did.

The stock 305 bore is an odd number and I believe it may have been a metric dimension....

Most other GM engines were based on std. fractional sizes....

Only other odd one I can think of is a 396 bore.....4.093 ?

Metric 200 transmissions were used with the 305's.....

In the mid to late 1970's GM started using metric body bolts in some cars.....It was a pain to have to buy metric tools back then when everything else was std....

10-06-2015, 12:31 PM	#4
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,314 Likes: 25 Liked 544 Times in 213 Posts	Re: Gm performance 305 block The 305's came out when GM was going to change everything to the Metric system....but never really did. The stock 305 bore is an odd number and I believe it may have been a metric dimension.... Most other GM engines were based on std. fractional sizes.... Only other odd one I can think of is a 396 bore.....4.093 ? Metric 200 transmissions were used with the 305's..... In the mid to late 1970's GM started using metric body bolts in some cars.....It was a pain to have to buy metric tools back then when everything else was std.... __________________ Rich Biebel S/C 1479 Stock 147R