I want a "plug and play" 350 for my 87 IROC with a 305. The car has an automatic, and 3.23 rear end. The GM Goodwrench website has one called the 350/ 300HP for around $2300. Can I just go to the dealership, buy this motor, and swap all my current engines stuff over? If so, what kind of 1/4 mile times could I expect? I'd like to see at least mid 14's. Thanks.

 

There might be a couple of parts that dont swap over, like the knock sensor/module, the injectors, maybe the ECM. But for the most part, it should be a straight swap.

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1989 IROC-Z 5.7L
NOS 150HP kit
ProBuilt 700R4, PI Vigilante 2800 stall lockup
Baer Brakes 12" Sport System

 

I got the Crate ZZ4 I had the stock 305 TPI put on it cus I didn't have the $$$ for Lingenfelter. The had to oblong 4 of the 8 holes in the intake to get it to fit. But other than that it worked. What kind af fuel injection are you running? My eng. dynoed @ 355hp & 405 lbtq. w/ a carb. People tell me it dropped to 315hp when I put on the stock intake sys. This is only hearsay I've never been on the dyno yet. I'm planning a SuperRam in the near future. Keep us updated on the install.

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Mods: ZZ4 engine w/stock TPI, adj, fuel pres. reg., MSD 8.5, HI6S ign. w/ PS-91 coil, K&N filter, TPI air foil, Hooker comp. shorties, American Thunder flows. 160* stat., TB bypass.

 

I'm running the bone stock 87 305 TPI system with the cold start injector. I was told by a guy at a speed shop today that that the GM 350/300HP is no longer available, and hasn't been for a year. Yet this engine is advertised as being available from every GM engine dealer on the internet. Is this true? They also said the ZZ4 won't work with TPI unless you change the heads and cam, which seems ridiculas. That's what you're paying for is the heads.

 

You can get a GM L98 (5.7) short block for $1150, and then put a set of heads on it, and a cam and make your own combo.

That would easily put you into the high 13's.
My 87 IROC which is basically stock, is running 14.4 on an L98 with 160,000 miles on it. Better heads and and cam would easily break into the 13's.

Also, an 85-86 TPI intake would fit the older style heads without any modifications that the shop mentioned.

 

if your going gm just for convienience don't bother.you can get a 383 stroker short block for 1200 with quality internals from speed'o'motive,or any reputable company it's what i should have done to mine considering the cash i spent.good luck

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87 trans am,gm crate 350(4 bolt mains 10to1),L98 aluminum heads,LT4 hot cam,slp runners,slp 1 5/8 headers,3in.y-pipe,edelbrock base,hi flo cat,air foil,afpr,as&m ported plenum,gutted airbox,t-5 tranny w/centerforce clutch and a 3.27 9bolt(11.9in. brakes),ed wright's fastchip,relocated iat sensor,160 fan switch,tb bypass,accel supercoil,cap& rotor,hollowed maf,slp 3in. catback,a/c delete.

shooting for 13's!!!!!!!

14.10@97mph w/2.01 60'(auto ET)

slp catback is finally on!!!
fastchip prom is in.
kicks you in the *** at wot.
FLOWMASTER S.U.C.K.S

 

SpeedoMotive is not a reputable company, see the thread in the Vendors forum.

The ZZ4 engine works great with TPI, I used a ZZ4 cam and heads on a 350 shortblock in my car and it went low 13's. Many other TPI owners have had success with ZZ4 engines as well. The only thing is the heads have the 86 and older intake bolt pattern, and no EGR passages. I solved that by using a TPIS intake manifold (any aftermarket intake manifold has the right bolt holes for both style heads) and modifying my SLP headers to use a Corvette style EGR (which every aftermarket intake manifold has too). However if I were to do it again, I wouldnt use the ZZ4 heads, as they're not that good.

I would start with any roller 350 block and add your own heads and cam. I've seen good results with AFR, Trick Flow, and Edelbrock heads. GMPP also has three great roller cams, the ZZ4, the 845, and the LT4 HOT cam. They cost $200 or less too.


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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
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