I have talked to several people that sell this engine and they told me that it has upwords of 260 HP with headers and a 4 barrel but my question is how much HP increase could be gained by a cam swap like a muscle car blue print cam for a 350 with 350 HP. Also would the heads on this engine accomadate this well enough.
Thanks Fellow Hot Rodders

 

That motor isn't a hot rod piece. It's a basic replacement for worn-out truck motors and the like. It's not "bad" or anything, it's just that it only is what it is, which isn't much. You might as well start out a high-perf buildup with a 350 2-barrel out of a 74 Impala, that's roughly what it is.

That cam won't give you that kind of HP in any motor. The HP rating for that motor was generated the old way, and is, shall we say, highly optimistic by today's standards. The cam is about 40 years obsolete. It wasn't even that good of a cam in its day, and like most of the old cams from before the valve spring technology that has come along since, it has too little lift and .050" duration for the amount of total ("advertised") duration it has. Very lazy ramps. You can do a whole lot better with a modern cam.

The cam that comes in it is probably the old .390"/.410" POS that came in run-of-the-mill 350s and other motors throughout the late 60s and early 70s. Also a terrible cam.

The heads on that motor are horse dung. IIRC they are made-in-Mexico copies of the 882 casting. Highly anti-performance.

Get a Comp XE268H, you won't be disappointed. It might get you to the 300 HP mark. At that point, the heads run out of flow, and it won't matter how much more cam you slide into it, it won't help and instead will probably hurt.

The strong point of a motor of that sort is that it's built for low-end torque, raw grunt. That's what most of the people who buy them are looking for. It's never going to be a deep-breathing high-RPM horsepower kind of thing. You'll do better if you play to its strengths, because to correct its weaknesses (dish pistons, crappy heads, piddly cam) you will spend more than just building up a junk core the way you want it.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Geesh, now I wish my 305 would have blew up a couple months later so I could have afforded the ZZ4. Really though it's a decent motor if you have to have one, but I if I hadn't needed it then I would have saved up for a better motor. The redline by the way is only 5200 rpm, which I am guessing will hinder high out put power.

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'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
FLOWMASTER, NO CAT
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
2:73 GEARS
Rebuilt 700R4, with manual valve body
B&M Megashifter
Soon to be installed
3:73 Richmond Gears and 3" Hooker Aero Chamber
15.61@ 95.2mph G-Teched, need tranny work
"There is nothing more addicting than speed"