i'm trying to get some good info before i spend my money on something that will not work well. So please any help will be appreciated I have a 350 block stock deck/bore, with flat top pistons with 4 valve releives, i want a solid 400rwhp in my 89trans am with a t56 and 3.73s so i'm guessing that would be around 480ish?? flywheel hp i dont want my comp above 11:1 b/c i will be running 93 octane. heads will be pro comp: 190cc -> 56cc? 58cc? 60cc? and will the XR288HR be good enough for my goal? any better cam?? air gap intake or vitor jr? or edelbrock rpm?? thanks in advance and please help me

First IMO
Asking for 400whp out of a standard bore 350 one what i would assume to be the stock low comp. 4 valve relief pistons is a little of a stretch. Secondly, when it comes to engine parts you get what you pay for. Pro Comp heads arent the best bang for the buck out there. There is a whole lot of reviews on them and The Boat shop Dyno tested some and have a huge story on them if you google it. The pistons you have will end you up about 9.3-9.5:1 on a 64cc head.

I would pick up a set of 5cc flat tops and cut the block 30 over. Should net you around 10.5:1 on a 64cc head.

Patriot Performance has a set of 190cc heads with roller springs good to .620 lift for around $950 which is a steal.

The xr288hr is a nice cam, but id guess around 450 crank hp tops with that cam and the patriot heads with a victor jr. Running a single plane intake on a small cubic engine with a larger cam is a pain drivig on the street. The engine in my car is similar to what you have but im running world s/r heads, torker 2 intake, and a 228/228 crane flat tappet cam.... and my engine is a pig is low speed traffic. If i could do it all over again i would use the rpm air gap.

Its going to be hard with off the shelf parts to hit a 500 hp goal and still keep it streetable in anything under 383ci. Orr89roc Made close to that on a built afr headed 383 with a custom cam.

my block is stock but my pistons are aftermarket flat tops.

I was planning on milling the head down to like 60cc to make up for the small cubes

Milling the heads to make more compression isnt the best way to go about it. Keep in mind excesive milling, angle or not will require you re align the intake face. If your pistons are completely flat other than the 4 valve reliefs, you probably have a 7cc piston which should be about 10:1 on a 64cc head.

If you dont want any machine work on the block, summit sell some -3.5 cc dome pistons. These will give you damn close to 11:1 on a 64cc head.

Milling heads isn't always a good idea....you can ruin the quenche (spell error...pronounced kw-inch) in the combustion chamber....also I bought a set of pro-comp heads..and they were cheap yeah...but worked....I had mine custom ported (60hrs worth)...which I could of bought a good set of AFR CNC heads after that..but now mine flow well...check out my signature below for my specs....I put 457 down on dyno..that might give ya a little idea too.

if I would have stroked motor (ran out of money)...it might of hit 500hp or somewhere near there....who knows

my 383 combo i made 470 horsepower. It will be very hard to make 500 horse on a na engine

I know he didn't mention it, but wouldn't a Superchaerger and/or NOS setup take him well over the 500 mark. I see "91iZ" is almost hitting 500, so if he added a setup for a SC and/or NOS, 500 doesnt seem to hard anymore.

Im really just stating this because someone had their 305tbi hitting close to 500 as well NA (believe it was 430hp), and believe it was Fast355 (no longer has the 305tbi i believe). Yes it was a lot of work but it still made it into the range of what he wants and with a smaller motor.

afr 195 eliminator heads, minimum 10.5:1 compression, some type of roller cam, and a vic. jr. portmatched to the heads with a 750dp carb.

the xr288hr should be enough cam.. but those procomp heads would be the bottleneck.. sell those and go AFR, you will not regret it when you reach your goal..

my car, guessing a light weight of 3100lbs and my 116mph trap time, i should be making a minimum of 375rwhp with a very inefficient solid flat tappet cam and brodix racerite 200 heads.. with just a solid roller, i should be 400+rwhp.. add on afr heads and i'll be in the neighborhood of 425+rwhp.. btw, i'm runnin a 385 with 11:1 comp, ported vic. jr. and 750 mighty demon..

correction, i was running it..

pro comps only flow good after a lot of porting and clean-up work....

thanks for all the info.
In response to the S/C and NOS, i dont want nos mainly because my engine isnt really ready for it,and with the 6 speed i wouldnt feel comfortable. SCs are nice but not this time, ive had turbos and SCs before hence my user name No Boost=No Go but i need something dif. this time.

In response to the heads i know ProComps are not top of the line or even close to it, but for 600 bux i wanna see what they can do and where i can take them. Im the kinda guy that will bet on the underdog over the other ones just to see what they are capable of doing. Ive had good luck with it so far, ill keep my fingers crossed.

My dad works at a machine shop and works on CNCs and my brother and i have had him port and polish our heads before with great results so i'm sure he will help me out, if not i will be getting me a few sets of dremels

From the stuff ive read it seems to me like the PC 210cc 64cc will be my best option while keeping the same 64cc and not milling it.

BTW i will be getting some .030 over dome pistons just because achieving my goal with my flat tops wont be easy. My comp right now is ~9.4:1

a few more Qs:
1)my rods and crank are stock, will they handle the extra hp?
2)will the xr288hr be a decent cam for ~400rwhp? or are there better options?
3)will a -3.5cc dome pistons be enough with 64cc 210cc and xr288hr?
4)ive been recommended both the RPM AIR GAM and VICTOR JR, which one will work better for my goal?

what pistons do you have? stock bore?

get you rods fitted with ARP bolts.. they will not hold without them.. but IMO, i would go at least scat 9000 for the crank and forged i beams with ARP bolts for rods.. the stock stuff should hold but you're relying on stock parts to run mid 11's..

the xr288hr is a great cam, very capable of 400rwhp with the right combo..

your new comp ratio will be about 11.4:1 depending on you deck height.. i calculated zero deck, so a higher deck height will drop it.. and you probably dont want a hydraulic cam with that much compression.. hydraulic cams increase cylinder pressure at lower rpms, in your case maybe too much for pumpgas.. i would go for something near or slightly under 11:1 if you plan on staying with the cam..

the vic jr would be better suited for the task.. port the intake runner to match the gasket and you have a great intake..

I ran his numbers through a dynamic compression ratio calculator and yeah, at a 500ft elevation it is 8.5:1. That is with the 11.4:1 compression ratio. If he does not deck the block or if he decks it a runs a slightly thicker gasket he should be around 11:1 and somewhere in the 8.2-8.3 dynamic area which should be ok on 91-93 octane.

The reason i suggested the Rpm Air Gap is i assumed you would like reasonable street manners, the Victor jr will always make you the best power at the cost of low speed driveability. Its really your call, drop some hp up tp for low speed torque or vice versa.

GREAT INFO!! thanks alot

so it sounds like we're off to a good start. My block is the stock deck so just to be on the safe side i will get a thick headgasket. any recommendations??

Would i be better off buying a rotating assembly kit? or piecing it together like stated and taking it to a machine shop to get it balanced?

i found this kit on summit but the dome pistons are-4.00cc, is that ok?

http://store.summitracing.com/partde...5&autoview=sku

If you are going to pick up a complete rotating assembly, you might as well pick up a 383 kit with flat tops. Scat advertises a 11:1 compression ratio with stock deck height, not to mention the extra cubes will make that 500 hp goal a lot easier to get to.

Id stick with kits being that they are designed to work together. If you decide to pick the 383 kit, get it with 6" rods instead of the 5.7" rods. The longer rod will reduce the load on the bore as the piston is moving up and down it.

Top off the 383 with some nice afr195s and a victor jr with the xr288hr and you should be damn close to the 500 hp mark. The procomps will more than likely choke you down to 450hp at best.

Another thing to remember is not to run a thick head gasket on a un decked block, this will destroy the quench area and hp will suffer for it.

considering that my car is a 6 speed and has a flywheel instead of a flexplate, most kits that ive seen come externally balanced with flexplates.

Ive never dealt with balancing rotating assemblies before, never had the need to so what would be better externally balanced and swapping out the flexplate with my stock flywheel or get one thats not balanced and take it to a shop with my flywheel and get them to balance it?

i have a suggestion. take the heads from a 454 that has been bored out to 500+ ci. then take ke the heads and put them in the engine compartment. then place a bored and stroked 454 under them. on top of the heads put a nice hot direct drive blower. there you go. nice and simple. dont worry about over working a 350. go all the way.
i dont want to be too sarcastic, but this is one of those times if you really want the hp dont screw around.
how does 60 to 150 in 2 seconds sound?
are 3 seconds to 60.
want a hot rod - make a hot rod.

Most of the Scat kits for 1 pc rear main seal block state they balance with a stock balace flywheel, which is externally balanced to begin with. Almost of those rotating assemblies need to be balanced anyways.

tony- Though you are right about big blocks topped with a blower, he stated he wants an all motor car, and being that he already has the block to work with, why not? Also, its not the easiest thing to get a big block into a thirdgen and retain most creature comforts. Another thing is cost, even mild big blocks cost more hands down to built small blocks.

Best bet is gonna be to deck that block, run a stroker crank for 383, and PC210 heads if you want to stick with Pro Comp... Else get better heads and make more power with less cam and be much more streetable

If your dead on 350 inches, 190's probly be ok. They flow ok from what i've seen, not great but should be enough for near 500hp. If you can afford to get better heads, DO IT. Heads make power and most of your money should be spent there.

XR288 is a big cam for a 350. Its better for a 383 and will make around 480 or so hp on a 383. Maybe 500 depending on the heads and intake. For a 350, That cam will be abit rough. Definately run those heads milled down abit to like 60-62cc. 62cc, .028 gasket on standard deck block will give 10.8 to 1 compression with 5cc flattops. 7cc flats will make 10.55 to 1. Definately trying to stay close to 11 with that cam.

Another option I'd look into over that grind is the GM847 cam. 232/242 on a 112. Abit more friendly but not too far off that 288hr. cheaper, you can find them used alot of the times as its a popular LT1/LT4 grind. That cam will rev up and make near 400whp on a 350 with those heads. Mild stock ported heads/LT1 guys do good numbers with that cam.
I'd run vic jr if your not worried about low end too much. Either of those cams will want and NEED to rev up over 6500 anyway on a 350, so run a manifold that will help that out.


For what its worth tho, you can run a smaller 224/230 type cam with AFR 195's or similar and make the same power. GTA Matt is doing high 11's at 116 with that same combo on a stock L98 bottom end with miniram intake. Thats 3-4mph shy of my 383 with same heads and a much larger 230/245 cam. I made 400whp. Smaller cam, better heads make same power and does it with less rpm and much more streetable. I'd recommend good heads and a 383 if at all possible with your setup

ok so now i'm def. talked out of the pro comps period.

Honestly i'm not really on a tight budget because i dont need the car and dont have to spend all my money now. Less than a month ago i spent 2k on the t56 swap and its already paid off.

I would like to stay close to 1100 on the heads, from what i keep hearing AFRs 195cc eliminator are a great set but ~1440bux but if those are the ones that would make the most power with the cam and intake for specs then...


any other great options as far as heads?

So far i think we've settled for the VICTOR JR intake manifold and the xr288hr cam

The extra 350 you will spend on the afr heads will pay off in the long run. They have proven themselves on many engine builds.

If you really want to stay in the 1100 range, look into brodix IK200 heads or patriot performance 190cc heads. Both companies offer spring upgrades for hydraulic rollers.

There are a couple of deals on AFR heads on this board. Heads is where the power is at.

i am going to run the xfi-292 on my 355, with afr 1038's, i plan to go with keith black 3.5cc flattops and order the appropriate head gasket for quench...

compression will be in the 9.2 to 9.4 range but i plan to add a healthy dose of nos or boost... it's all in the details my good man...

imo, 383 is alot of headaches if ya don't know what ya doing.... alot of clearncing, maybe a small base circle cam, which nessistates longer pushrods.... but like said above, heads are everything, and afr is where it's at!

brodix IK200's are not bad either.. but they still over 1100 i think.

Just about any head worth buyin is over 1100 if its aluminum. I just suggest you pay for the heads now because they are worth it in the end. You cant go wrong with good heads

ok so i will go with the AFRs
AFR# 1034 - 195cc Heads, Straight Plug, 65cc, .600 lift


So here what i plan on getting:

AFR 195cc heads
xr288hr
victor jr
holley 750
eagle or scat forged 355 rotating assembly with dome pistons, i beam rods,

The first thing i will do is get the heads/intake/carb and put that on my current setup flat tops .212/.218 @.050 .488/.488 +1.6 rr and race it, i will hold off on the cam since my comp. will not suffice its needs with the flat tops.

Attendin school and work full time will not give me enough time to put together the engine, break it in, and race it this summer. So i will pick up another 350block 4bolt main like mine and put it together on the side and put the cam in this one, and once im done with that block i will put my top end on it (heads, intake) and drop it in the car. I might even get splayed caps for it.

I will be keeping my current block with the flat tops as a spare block just in case.
Seems like this season i will not have a 500hp engine under my hood but i def. will by next.

the afr flat tops and .212/.218 .488/.488 and victor jr, where would that get me? j/w

if you're looking at the IK200's take a look at the summit heads, i believe they're rebox brodix

Thats usually how it works, summit parts are just reboxed other stuff. Jegs has heads too which I believe are canfields which are also a good set of heads

Probly be abit dissapointed in that setup since the intake and heads are better suited for the bigger cam and compression, but should still run ok. I would hope high 12's out of that setup since its abit stronger than a bolt on L98 and L98 with bolt ons is capable of high 12's

You can get away with regular caps just use a stud kit on the caps and torque them down good. 4 bolts with studs are good to 700hp or so before the caps walk abit. Splayed are for abit more power. But its nice to build that motor on the side and drop it in when your ready. Keep the car on the road and enjoy it.

But like i've said earlier, if your going 355 rotating kit, a 383 isnt that much more

mmhmm good point

When you have an oppurtunity for cubes, take them... THey help make power so might as well add them in when you can. Bigger is indeed better

the brodix ik200 is very similar to the racerite 200's i have.. and like i stated, i have a not so efficient cam design thats putting me in the 465hp range..

might i add that i am running a choked 2.5" true dual exhaust and a better exhaust could probably give me anywhere from 10-15 rwhp?? so 485hp is very seeable in my combo alone.. add just a roller cam and i'll be seeing over 500hp at the flywheel..

Exactly.... get rid of the 350 and get a 400 block and build that! Easier to get a little more power out of it as well as a boatload of extra torque.

My last build was a flat topped 406 with 215cc/64cc Dart Platinums, Air gap rpm hogged out a little, proform 850 double pumper, and a flat tappet (!!!) cam coming in at 241º/249º and .525"/.549" on a 110. On motor I was able to squeeze out a 12.1 in a slightly under stock weight 88 Monte Carlo SS with a built TH-350 and 3.73's... This combo had a pretty tight quench and was running premium with full timing with 11.4:1 compression.

Extra cubic inches will make it to where you don't have to have the best of components to get your sled going in a hurry and makes a somewhat radical combo for a smaller size motor into a more tamed, streetable setup.