Titan907

Can you run 1.6 roller rockers with the stock cam and valve spring setup? Thanks again for all the feedback.

Captain YARRR

I have twin 383s being built now and so far are doing real well. The tune isn't dialed in yet but I'm pleased with the first pull already. But they are all right about what needs to be done to make power.

That said...if I had a single, I would be very tempted to keep my 350 in the boat and start putting together an LSx. Huge aftermarket, much easier to make north of 400 with little effort. Looks like you are already planning on buying headers so that's not a concern. Then when you have it done, swap it in and rock out.

Wes Burmark

01scarab29 I'm betting you are leaving some horsepower on the table with the stock throttle-bodies. One of the pro builders (sorry I can't remember who - but very helpful) said the stock throttle-bodies would pull vacuum in hopped up 377/383s and needed to be replaced by larger unit(s). I'm guessing there is another 3 m.p.h. in your combo. Curious as to how much you invested.

Trash

I'm not sure of the TB size for the 1998 motors, but the earlier 95 motors used the same throttle body on the big blocks. I'd dare say the TB is not the choke point or limiting factor. I got a 10-12 mph increase over my stock SBC. It was a complete rebuild, as others have noted, cam, stroke, heads and tune combined net the most results. Stock intake and exhaust (thru-hull) were kept.