Asaltweapon is running a 4.5 crank, I personally would use a 6.7 rod in a tall deck block for that application. I'm not an engine builder, I was just curious. I've played with a couple BBC's with Prochargers, definitely not an expert.

While the blocks stroke thus displacement isnt up for debate, the camshaft is the focus of this post. Any info. related to the cam choice is welcome. I already own the 4.5x4.5 block. TIA

I don't know anything about the Merlin heads, Prochargers seem to like the 112 lobe separation.

Thats good info. Thanks

i think the best thing is to give bullet cams a call they have made all our marine cams even a blown 598 turning backwards they are the best and are great on the phone they even build many nitro cams for many teams..... they do have the knowledge to guide you

I've focused my attention the last couple months on making cam, valvetrain and valvespring selection easier.

allmondmarine.com/cams/

The chart on this page is focused on N/A power. Boosted peak power speeds will be several hundred RPM higher.

On each of the individual camshaft's pages, there is a valvetrain recommendation based on what you expect your max engine speed to be.

I'm working to make these cams available soon.

I've also built a valvespring calculator that I and others find quite useful: Spring Calculator

Really neat and informative site. Never heard of them til now. Rockers look exceptional. I focused on their stage 5 cam.

OP - Whats your peak rpm goal + - ? My jones SR cams are 255/259-724/724 in my NA 565’s peak @ 6k. 4.25 stroke but I’d guess in a FI 4.5 stroke would be near the same.

I am surprised they use std journals on all. Std lifter size or .904

6,500

I would have went with Mike but it was Covid and his cams were weeks out Comp had cams in stock .

https://www.yellowbullet.com/threads...s-cams.245015/

Hopefully those shlt show times are behind us. But yes Mike is a great guy to deal with and been around for a minute. Lol! I filled out his form and he got right back with me. (Beginning of Covid) and lucked out. I was very glad I went with him and their lifters as well. Cams were spot on and at that time I was so sick and tired of laying head down on the pillows at night and wouldn’t stop thinking about cam specs. I was finally done with and extremely happy! The plus side was they sound absolutely wicked to boot. 😂

He comes from the “OG”old school lunati, ultradyne / bullet crew (era). But stays with current times as well.

Like bangbros mentioned bullet is a great Co also.

Nothing against comp at all but there’s much more out there than just comp and you get more of a one on one care which these days are slim to none.