wesrams1

Would the 305 in my 1992 camaro RS be a 4 bolt main? How can you tell?

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Jeff91RS

No. The one from my 91 RS was 2 bolt. I am fairly certain that all 305 blocks have always been 2 bolt.

gregsz-28

AFAIK there were never any 4-bolt main 305's built, but any SBC can be converted to 4-bolt mains.

wesrams1

so if im dropping in a 350 would i have to drop in a 2 bolt main engine? or could i drop in a 4 bolt main in?

Jeff91RS

The amount of bolts on the main caps doesn't matter when it comes to engine swaps. A 2 bolt and 4 bolt block could not be differentiated from unless the oil pan was off or they ran the numbers, and even some casting numbers cover both 2 and 4. 2 or 4 bolt main refers to the quantity of bolts that hold each main cap to the block. There is a benefit of 4 bolt main at higher power outputs but for the average engine 2 bolts works fine.

As someone else mentioned you can convert a 2 bolt block to a 4 bolt if need be and I believe they have more strength because the outer bolts are installed at an angle.

Long story short, don't let the quantity of main cap bolts deter you from an engine swap.

gregsz-28

No they aren't, unless an aftermarket block or main caps are used, and aftermarket main caps with the angled outer bolts can't be used on stock 4-bolt main blocks.

Jeff91RS

Thats what I was talking about by referencing your original post.

gregsz-28

I just re-read your post and realized that I initially misunderstood the second paragraph.

wesrams1

alright thanks alot guys, youve all helped alot

five7kid

Some were made for use in vans. Pretty rare, though.