Ive got a 1991 rally sport with 40k miles on its stock 305. i just purchased for 200 bucks a 305 with many edelbrock and holley parts i took it down to the local motor shop and had them clean it up and bore it .030 over here are my few questions. oh btw the block is a 1978-79 chevy 305 and im keeping the TBI set up i have ordered a mounting piece so i can use the edelbrock intake and the distributor along with maintain computer controll

1. what is my new motor size im hearing different things im told im now a 310 or a 315

2. will my brackets such as alternator and powersteering fit on the older block

3. will i need a new starter or can i reuse the one i have

im going to revise this tomorrow but any answers are great

 

Rather than give you a fish, let's teach you to fish.

The original bore size of a 305 is 3.736". The over-bore was 0.030", not 0.30". So, 3.736" + 0.030" = ?

The volume of a cylinder is the area of the base times the height. The area of a circle is pi x radius squared - radius is 1/2 the diameter which means 1/2 the bore (use the new bore, not the old bore). Pi is approximately 3.14159. The height is the stroke, which in a 305 is 3.48". There are 8 cylinders, so multiply the cylinder volume you just obtained by 8. What did you get? 310.11-ish, right?

Using the older block will only change the rear main seal type (and therefore the flexplate type), and the location of the dipstick. For the flexplate, use one for the '83-'85 f-body V8 application (about $35 or so), and your original starter will work. The dipstick problem is best solved by installing headers (if you don't have them already).

 

lol its nice to have it explained to me noone ive talked to in person has been able to explain it like you did thanks alot five7