Advice on 409 rebuild

[W-motorhead]

Dear 348-409ers,
The leaky rear main seal in my '63 409/425hp is annoying me enough to inspire a rebuild. I hope to tap the vast, collective knowledge of the 348-409 group to plan the project. As you all know, the engine was designed to run aggressively, but pump gas is not suitable for the 11.0:1 compression. For that reason, I would prefer to tune the engine down during the rebuild. I don't race. I just rumble around town.
Aubrey Bruneau suggested selecting pistons to reduce compression to 10–10.5:1 and installing one of his custom hydraulic, flat tappet camshafts, which has the following specs: adv. duration (in/ex)=274/286, duration @.050" lift (in/ex)=230/236, lift (in/ex) .569/.547, max rpm=5800.
I have not succeeded in getting him to make that cam for me, so I have been looking for an alternative. The Classic THUMPR from Comp Cams (grind # 279TH7, adv. duration=278/296, duration @0.05" lift=226/241, lift=0.512/0.498) looks similar to the Bruneau design. Does anyone in the group have an opinion about this camshaft choice?
Many thanks,
Dan Fults

 

[Don Jacks]

Dan,Show-Cars has a very simular cam to what Aubrey suggested,pn 0954.I think that would be a better choice than the "Thumper".

 

[Iowa 409 Guy]

Dan

I'm running a Isky HR636 roller cam, .617 lift & .258 duration. 10.5-1 compression. Drives good on the street and not to bad at the strip.

 

[LMBRJQ 60]

Hi Dan,
I purchased a Cam and springs, retainers and keepers off Aubrey about a month ago.
No issues getting them, and im on the other side of the planet
Might be worth another call?? JMHO

Steve

 

[W-motorhead]

My camshaft and valve gear arrived. This is an Aubrey Bruneau-designed hydraulic flat tappet (duration @0.05" lift = 230/236 deg). It's too dang cold here in Salt Lake City to start a project now. I can only admire the hardware and the colorful Comp Cams boxes. Thanks to the members for advice, especially for directing me to the Show Cars website. It looks they have everything for a 409 rebuild.
Dan Fults