I am new to this forum, and look forward to being a regular.
I own a XaGt Hardtop, which is currently undergoing a ground up restoration.
I would like as much advice and opinions, on an engine combo that will give me approx 380-400HP. I will be using the original engine. I dont want to rev it past 6000-6200max. I am thinking of running a hydrualic cam, however i have not ruled out a solid. It will also have a Edelbrock Performer manifold (Dual Plane) , 780 Holley, Closed chamber 4V heads, possibly with tongues (if recommended and required) , standard storke and crank, standard rods with rod bolts,Hyperutectic Pistons+20, Extractors, Twin 2.5 inch exhaust, and X pipe. I is backed by a Toploader and 3.5 nine inch.
Does anyone know of a true and tried combo, similar to the above, that will produce good torque, and around400HP?
Have a look @ the Blueracer cams that Crane sells. I know the largest Hyd listed will do your 380hp figure. Your only pit fall is you manifold and carb will hurt hp but torque will be good. A crane F238 solid cam will the figures you want easily too. It'll max rpm @ 6200-6300rpm. The downfall of the solid is your in the realms of a diff ratio change.
Make sure he carb you have isn't a spreadbore. The squarebores in my experience work better on a cleveland. Better torque down low.
The carb is a 780 square bore. Have heard solids are a bit more reliable than hydraulics though? I also want a rough idle, i hate water pump style idles.The F238 sounds the go. Would it still work with 4V heads?
If your leaning toward the F238 you'll need to change the diff gears. 3.5's borderline with the hydraulic cam but passable. 3.5's just won't work well with an F238. 4.11's work well with them. Combo's for F238's are 3500/4000rpm stall and 4.11's. It'll work with the 4V's just fine. This combo means you'll probably end up spending more than you'd like.
The hydaulic cam I know works well with a 3000rpm covertor and 3.7's. 3.5's will be fine though. I'd be going this way if your going to drive it a lot. This combo works with what you have. This one has a lumpy idle
Another 400-450hp combo that is very common with 4V's is Crane F246/4500rpm convertor and 4.11 gears. It's a reliable combo but with todays fuel prices it's expensive.
Once you start getting into solid camshafts you have to make sure the fuel system can keep up. Even more $.
This is my combination and there are a few others on this forum with a very similar combination. With a manual and 3.5:1 diff ratio, this combination has heaps of vacuum to run the brakes. It will pull from idle like a stock 351C does with a 3:1 diff ratio. It will pull away from idle in 3rd gear with no hesitation. It will allow gear changes at 6500rpm. Top speed with 3.5 gears is about 230 km/h. Fuel economy is comparable to a stock 351C. Basically this is a have your cake and eat it combination.
Hypatech hypereutectic pistons
Torque plate hone
C.O.M.E. CLS138 solid camshaft (Crane F238 is a similar alternative, but not as good)
Single valve springs (if using the CLS138)
Yella Terra Bolt on adjustable rockers
302C heads, home ported, single piece valves.
Holley 750HP (jets are right out of the box)
MSD 6AL (mainly for the rev limiter, set at a minimum of 6500rpm)
Pacemaker Tri Y's (easy to pick up 2nd hand)
Dyno tune - carb jetting and distributor curve
Upgraded fuel line and pump.
My combo will be similar, although im running a performer manifold , and 11.0:1 comp,780holley,and 4v heads. I want to make sure the combo i choose will work well with 4V 's. I am also leaning towards Try y's .
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