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bbc 2 bolt to 4 bolt caps?

Posted: Wed Jan 01, 2014 8:35 pm
by mikeT
I have a 70s 454 2 bolt block. Gonna convert to 4 bolt mains. Have eagle caps and wonder why most aftermarket caps only change the 3 center caps? while the factory 4 bolt blocks have 4 bolt cap on front? At what level should you also change the front cap to 4 bolt? Anybody been down this road? Also I would love to get a world or dart block but its not in the budget.

Re: bbc 2 bolt to 4 bolt caps?

Posted: Thu Jan 02, 2014 6:38 am
by John_Heard
Mike I've never converted one over, but thought I'd comment that I've seen some 2 bolt main big blocks get the crap beat out of them and survive. One of our members is spraying a healthy shot of nitrous on his 2 bolt main 496 and it's held together for a long time. It does have cap walk but hasn't hurt bearings yet that I'm aware of.

Maybe save the align hone costs and save that money towards a new block and use what you have?

Re: bbc 2 bolt to 4 bolt caps needed?

Posted: Thu Jan 02, 2014 4:45 pm
by mikeT
Thanks for the reply John!
The engine is a 461, It has good internals, callies crank, lunati rods, JE pistons . The cam is a solid flat tappet .660" lift.
It has edelbrock performer RPM-454R rect port heads that have been ported, with an Old weiand Team G manifold & 1050 dominator
It dynoed 686hp at 6600 rpm. I shift it at 6800 . In the car (tube chassis with glide & 4.88 gear 33" tire at 2650lbs). it has been as fast as 9.21 at 146
I want to see if I can step it up with a roller cam and edelbrock victor#2907 intake to get it in the 8s?
I know I will have to turn it alot higher to get more HP? Thats why Im not sure about the 2 bolt mains?

Re: bbc 2 bolt to 4 bolt caps?

Posted: Thu Jan 02, 2014 5:09 pm
by John_Heard
I'd bet you can crank it on up. Has to be a lot easier on it than a big shot of nitrous would be.

Re: bbc 2 bolt to 4 bolt caps?

Posted: Sat Jan 04, 2014 7:53 pm
by bracketchev1221
I've had 2 bolts with main studs to 7500, my dad had his to 8000. The center caps are a big help to upgrade.

Re: bbc 2 bolt to 4 bolt caps?

Posted: Mon Jan 20, 2014 5:10 pm
by 79 Camaro
Save your money and don't convert you stock block 2 bolt to a 4 bolt.. I am the member that John Heard was talking about. I have been spraying my 496 for 7+ years with no major issues. Been putting 350+ to it and it does have some main cap walk, but it is not to the point of hurting the bearings at all. Save your money and buy a aftermarket block. If you have any other questions, let me know.



Adam Wright

Re: bbc 2 bolt to 4 bolt caps?

Posted: Thu Jan 23, 2014 9:35 pm
by BracketNova
I went ahead and put the Milodon splayed caps on mine. BUT, I got an untouched 289 block for free that I started from. The 289 castings are supposed to be some of the thickest GM blocks and high nickel too. Not sure how they would stack up against a darrt block though???