I'm trying to plan out my next engine build for an '86 IROC-Z that will see a lot of summertime DD use. I'm currently running a 350 with performer rpm heads (64cc), a Crane compucam, stock TPI (other than injectors, FPR and air foil) and a full Edelbrock exhaust. It runs very strong, but as expected, the top end is weak in comparison with the rest of the powerband. Rather than upgrading the current motor, I would rather build a new one and have it ready to go so the car can be driven in the meantime.

I have a 350 4bolt main factory roller motor that I would like to rebuild with a 383 stroker kit. I also want to try the Edelbrock E-tec 200 heads along with a Vortec TPI base and SLP runners. Should I stick with around 10:1 compression, or can I bump it up a little more? My current setup is capable of running on 87, but normally I stick with mid or prem just to be safe. What would be a recommendation for a cam, XFI 268? Will my current 24 lb injectors be enough? I'm not sure if I will keep the Edelbrock TES, may go with a set of longtubes. Anyone see a problem with my plans?

 

E-tec 200's are ok but if you afford to get others, then do so.

SLP runners, siamese them some more to help that 383 breath.

XFI268 is a mild cam in a 383 but should fit your goals well. 10.1 to 1 is fine but you can go alittle more. 10.3-10.5 should be ok. 11 to 1 will require a bigger cam to keep dynamic compression down. If you siamese those runners you could just about step up to the XFI280 cam if you want to run that lineup. there are many cams that are in the same league that will work.

If you want i'd get a custom grind for that setup but that cam will depend on how siamesed the SLP runners are.

24's should work for up to 350whp. Any more than that which can be possible with fully siamesed/ported base and good heads with a supporting cam, then i'd go 30lbs

 

OK, one of the 383 kits listed at Jeg's was showing 10.7:1, IIRC.

What heads would you recommend? The RPM's seem nice for the money, that's a big reason I was thinking of staying with Edelbrock. I've never done any type of porting before, so that will likely be kept to a minimum. Only thing I've done like that is remove the wall in the plenum, behind the TB.

That's another thing, will I still be OK to keep the stock TB?

 

For less money than the price of the E-tecs & Scoggin-Dicky base, you could get a set of 23 degree trick flow heads or a set of the smog legal AFR heads. A large base and runners will set you back some more, but you can run your stock pieces if you are short of funds while you save for the large base and runers. Edelbrock greatly exagerates the specs on their heads. To get a set of E-tecs to flow like Edelbrock claims will take a lot of port work.

 

I don't want to reuse the stock base, even for a short amount of time. That was the plan with the current motor, but I never had a chance to get to it. I have a feeling that would happen again if I don't do it all at once

Also doesn't need to be smog legal, the EGR and function has been deleted already. Would the AFR 210cc Race (65cc chamber) be too much for a street 383?

 

If not smog legal then go with stealth ram or better.

210's are alittle big for street 383. Now if you want a bigger cam thats still streetable yet makes power to 6500 rpm, then go AFR 210's. you'll make a crap ton of power.

my "street" 383 was a 195 AFR motor with stealth ram. Runs mid 11's in the 1/4 on motor, mid 10's on nitrous. Idle was mean but the car was very driveable yet loud.

If you dont want to go that far into it, then back off with a smaller cam and lower compression. Still gonna be good for low 12's possible high 11 pass.

 

I also forgot to mention that I'm one of those nuts that thinks keeping "the look" of the stock TPI is very important. I like keeping the car stock appearing as much as possible. The more this discussion continues, the more I like the idea of the AFR 210's and a larger cam, but certainly don't want to choke it with a restrictive intake. The First Injection setup is appealing to me, but there doesn't seem to be much info on how well it performs.

 

It will perform just like the other large tube systems but probly abit better since its even larger. If you do TPI i'd go with a 195cc head. 210's are better suited for miniram/stealthram setups that will pull more rpm.

 

At the moment, the car has a built 700r4 (but it's dead) and the stock 3.23 rear gears. When the weather warms up, I will be swapping to a T56. Will this combo be happier behind a higher revving motor (non-TPI style)? Or will it just be more fun to drive?

 

those gears are abit tall for a T56 and this motor build but for a TPI style 383 that makes good low end power, you dont need alot of gear, nor do you want it as you'll run out of rpm at the track with a 26" tall tire

Wide gear spread of the automatic likes broad torque curve combos. T56 with tighter spread will like just about anything since the rpm drop between shifts isnt that bad. It will be fun to drive with a stick but doesnt mean you have to have a rev happy motor to make it work.

 

OK, thanks for the advice. I guess the best thing to do is wait until the t56 is in the car before I decide exactly what I want to do. Even if I find myself looking for more rpm, I would really like to try the First setup. Then if I'm not happy with it, I'll bite the bullet and go with a stealth ram. I could just use the First unit on one of my other cars.

 

HSR is a great intake and really shines with abit higher revving motors as it will support peak power in the 6000+rpm range. BUT if you were to use it on a mild motor, it still be a good intake and make good power

I had the HSR on my stock L98 with the basic bolt ons and it picked up ALOT over stock TPI. You cant go wrong with HSR the first time around

First is a great setup for no more than 5500 rpm. HSR will go more than that and give you abit more options if you ever decide to upgrade later to better heads/bigger cam for more power/rpm

 

There seems like some good info on this thread. I'm also trying to build a 383 in my '89 Formula. I'm definitely going to go with an LT1 intake, but I'm not sure what cylinder head and cam combo to go with. Any thoughts would be appreciated.

 

383 TPI Vortec 10.5:1 tow motor.
regular gas!

 

Edelbrock part # 3892 would be sufficient for your 383 setup. This is what I'm going to use on my 383 tpi build (with dart heads). This part number includes the baseplate and high flow runners, then you can keep your stock plenum. I don't know how well the ports in the stock plenum match up to the Edelbrock runners, but it would be fun to find out and then siamese them if needed. As far as your camshaft is concerned, the MAIN thing you want to focus on is the lobe separation angle. For tuning tpi engines, the closer you are to 115 degrees, the easier it is to tune the beast, and the better your vacuum will be. Hope you get your project done soon, so I can see your numbers.