When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
2400 to 2800 torque converter with a shift kit and cooler would be the biggest bang for the buck if you are automatic and it's in good condition. After that maybe a First TPI intake and a governor kit for the increased powerband and shift points. 1.6 rockers and nice valve springs. Could be low 13s to high 12s with good street manners. Plenty fast for a street car and still look stock. Suspension mods and tires will help put the power down. It's a $lippery $lope once your bit by the mod bug.
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Originally Posted by ULTM8Z
Not sure what you mean by "big" cam. The stock TPI manifold will choke off anything much bigger than stock.
Somewhat agree but I'm sure the OP can effect results with a larger-than-stock but smaller than typical performance cam....For example, TPIS either makes (or used to make a "Super L98 cam". That camshaft is probably on their website OR you could find the specs with a general search. IIRC, it probably has about 10-15 deg more intake duration and even more exhaust duration.
Of course, if the OP is going to "crack" the engine to install a cam, there are a few intakes that will generate more power.. Superram, FFI (aka FIRST), Edelbrock, large-mouth TPI (AS&M), etc...
If someone still ports alum "113" heads, you could consider that, OR either of the (3) AFR 23-deg SBC head options: 180cc Eliminator, 195cc Eliminator, & 195cc Enforcer. ***
Since I think the '89's already had the "ZZ4 heads", I guess what I would do (in this order, at least based on my preferences for how much I'd want to tear into things)...
Updated intake and 1.6 rockers
2500 rpm converter
If more is wanted...
Heads and cam at the same time. For good street manners I'd probably stay below 220@.050. But that's my preference. Heads around the size of AFR 180cc.
I will comment on your Chip tune. I love C4's but you are about 25 years late on that one. For one not many can or will calibrate a car with a prom chip anymore. When you start building your own setup, that car really needs to be on a dyno to get the correct calibration for the prom and it is very time consuming to those that can do it. Time is money so for you it will also be expensive. My recommendation is to replace the ECM, you can use the Dynamic EFI programmable ECM. You will have to do some wiring harness changes but it is not difficult. It will also plug in directly to your wiring harness and you can use a wideband on it. It is programmable and it will also build your calibration file for you using feedback from the wide band. If you go with this you can pretty much build what you want and it will be much cheaper than a Holley ECU. I had them when I was at Zip, not sure if they still sell them but I would give them a call. If they don't have one in stock, just google Dynamic EFI