GMPP 350/290hp question.

[Rooster]

I'm thinking about purchasing a GMPP 350/290 hp crate engine for my 86 Cutlass. Already on hand, I have a set of '66 462 double hump heads rebuilt like new with 2.02/1.60 valves,.500 lift springs, heads are straight edge surfaced, 59cc combustion chambers. Also I have a Melling c-400-p camshaft(.447 lift,.222 dur. I belive the same grind as the old 327 "151" cam) just wondering if the double hump heads would work on this new engine to give it a bit more power, along with the cam.I'd probably be using an Edelbrock performer or Performer RPM intake,and a 600-670 holley or Edelbrock 600 cfm carb.Like most other people, I'm on a pretty tight budget.If the cam and heads that I already have wouldn't work,that's ok, I'll just utilize the whole new engine as it is. I know my CR will be up there, Just as long as I can use pump gas. Thanks in advance.

 

[megaladon6]

well the heads will work, but they are 40+year old technology. modern heads flow much better. you'd probably be better off with a set of stock vortecs. granted they only have 1.9/1.6 valves and need a specific intake, but they will almost certainly flow much better. and you can get larger ones or have bigger valves put in.
i think that engine starts out at 9:1 compression. with 59cc heads you're looking at about 11:1 which is acceptable on a street motor. you will probably have to run high octane fuel.
is that cam duration at .050? if so, it's about the same as the cam already in the engine.
i think you'll have about 325hp all due to the compression.
the way i see it, if you're buying a complete and new engine, don't touch it. partially because of if it ain't broke, don't fix it and also they have a warranty that you'd void. if you really want more power you can always build it yourself to save money.

 

[Rooster]

thanks for the reply. I'll probably use those heads(the double humps) on another engine project and not defile the crate engine, thus dorking up the warranty lol.
Any tips/suggestions on what intake and carb to go with? Also ignition, and exhaust info would be appreciated also. Summit has a combo/kit-Performer EPS intake, Edelbrock carb(elec choke), and gaskets and fastners for it,etc. Thinking about going with that. I'm thinking about going with MSD ignition.The 6A seems like it'd work well for my app. and an accel blueprint distributor.Maybe yall can tell me if im thinking on the right track...

 

[megaladon6]

i wouldn't bother with the 6a system. not on a daily driver. when you need every erg of spark energy, that's a different story.
i'd just get a regular vacuum and mechanical advance HEI distributor or you can get the MSD e-curve HEI. it's basically a self contained computer controlled dist that functions like a vac/mech adv one. but it's much easier to adjust and change curves on.
personally i like Q-jets, but the e-brock isn't a bad carb. and they're a lot cheaper to find a used one and rebuild it, IIRC mine cost about $300 for the tools, book, and kit.

 

[axisg]

nothing wrong with the Edelbrock. As far as the distributor I have rarely seen issues with the stock unit on cars that don't see over 6k redline. I have however seen a few aftermarket systems fail on a DD so that now makes me want to stock with stock up to a certain power level. Money would be better spent on a good cap, rotor, wires and coil IMO

 

[Rooster]

Any other tips/suggestions/experiences with this engine?

 

[jae]

Determine accessory-drive system, i.e. serpentine or v-belt This will help determine pulleys, brackets, water pump.

Cooling system, may want to take a look at it; at the very least flush the radiator / heater core and replace the hoses.

Exhaust is going to depend on if you running through stock, cat-type system, no cats, duals. So you'll have to decide mainfold or header, muffler (are you after sound, least back-pressure, ease of fitment...). People seem to like the Pypes system, 50/50 on Flowmaster mufflers, a lot like Dynomax

Don't cheap out on hoses, wires, thermostat, things like that. Most time when this happens the swap becomes a big pain simply because you cheaped out on a clamp, wire or reused old hoses.

Take your time with the swap. If there's something in the engine compartment that needs to be cleaned, repainted, or fixed perfect time to do it.

I think the main thing is overall goal of car and where you may want to upgrade later engine-wise. That'll help determine if this crate engine is for you or say the 350 H.O. or a ZZ4 long block then add vortec heads, whatever.

Good luck

 

[dogsht]

You will get more for your money and a better engine. Google Patriot performance engines.

 

[Rooster]

Engine will be here in two days, Just got my intake(Edelbrock performer EPS) and carb(Edel. 600cfm) yesterday.

 

[MD13ailey]

correct me if I'm wrong but the double hump heads dont have any mounting holes in them do they? so how do you plan to mount alternator and other things