Well I have this 2 bolt main chevy block,but would like to know if its worth to convert to a 4 bolt with aftermarket main caps. Would there be any issues and is there any diffrence between the 2 bolt than the 4bolt main?

 

Well the 2-bolt mains are much weaker than the 4-bolt. The after market Billet splayed caps are about the strongest out there. there stronger than the stock 4-bolt main because the two new bolts added are splayed outward. Stock 4-bolt caps have all 4 bolt going vertical.

If your going to drive it hard or make power, go with a 4-bolt splayed cap, better safe than sorry I always say.

 

From what I've read a 2 bolt block is good for 500 hp. A stock four bolt actually has a pretty weak spot in the main webbing(where the main caps bolt in) don't know what your combination is but upgrading from main studs to bolts is a good idea. But the splayed caps on a 2 bolt is the strongest way to go.

 

call Pro-Gram Engineering...they make great splayed caps for the conversion...with ARP studs and machine work, you'll spend 5 hun or close...if youre really wantin some power...buy a Dart block, never have block woes again

 

Great im leaning towards the splayed caps.Any ideas on how much the Machining might cost?Im assuming it will need to be line hone,etc.

 

the factory 4 bolts are so much weaker in the webbing area due to gm drilling the outer holes to deep. you will get less core shift and main cap walking due to the splayed outer bolts, and the holes will be in a beefier part of the main webbing.. your better off with the 2 bolt to 4 bolt conversion for max effort engines.

 

i agree with bluehawk 2 bolt to 4 bolt is much better especially with splayed bolts. if your gonna do it yourself make sure you get it line honed or just have a machine shop do the whole deal



80 TA 383 stroker- 11.90

 

I actually prefer to make 2 bolts studded,it helps the mains from walking,your never worried really about them lifting,so with a set of ARP Studs and a pinned 2 bolt block you should be all set!

 

If the factory 4 bolts were so weak, then how is (forgot his name) with the vette making over 1100 HP with a stock 4 bolt LT1 block?

 

my old machine shop guy had a street 383 with close to 500hp on 2-bolt mains with no prob, but if you go over, then splayed mains are a good choice, unless you are TRYING to grenede your engine....

 

2 bolt mains are find for most street/strip combos. I found a 4 bolt block and ended up adding ARP studs. Didn't need to but what the hell. You will be fine.

 

Depends on the rpm, it's harder on a 2-bolt block to go N/A past 7000rpm then it is to spray it or boost it at lower rpm's say 6000-6300rpm A 2-bolt block will work just fine for any street/strip action( 150shot/6-8lbs of boost), Just make sure you stud it with some ARP's. As far as the conversion...? I've never done it, then again I've blown up 2-bolt's @ 7300rpm, but never on the juice at 6300rpm.

 

i kinda like the safe than sorry route, i myself am debating on converting just because i dont wnt things to hold me bak from making more power in the future. hell right now im bout to sell my eagle cast crank and finda forged one.

 

What kind of power are you planning on making? I have a studded 2 bolt and it revs to 6800 without finching. I have noticed that a lot of people tend to go for the overkill in this department, which is fine if you need it but its easy to waste a lot of money if you dont.

 

i dunno bout him but i wanna go to 500hp/ 500ft/lbs but have room to expand.