1986 block, 1987 heads- CAM HELP - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bridgeman57 · 05-31-2020, 12:33 PM

I bough an engine with TBI and I’ve swapped it to carb. I want to put in a new camshaft but not sure what all I should replace because the cam in the block is setup for TBI. Because the degree would be off center a little. Would the stock cam be alright? And if I do add a cam, would I have to install new lifters, rods, valve springs, timing chain? Or would simply moving the cam timing a few degree be easier then spending roughly $500 more into a ****ty stock engine. Or just leave the cam alone and run it?

Suggestions and advice would be great.
Thanks

**THI** · 06-01-2020, 04:55 PM

The stock TBI cam is really small - around 179* intake duration @ .050" lift. The old 193* intake/202* exhaust cam used in the 307-400 small blocks is a big improvement and would work with the valve springs. The TBI heads are poor flowing heads so going too big on a cam would not work well. Many have had good luck with an RV cam (204*/214*)

**MikeB** · 06-10-2020, 08:49 PM

No reason the TBI cam won't work with a carb. But as mentioned above, it's quite small with an emphasis on low RPM torque. Something like a Summit Racing SUM-K1101 cam & kit would be an improvement, without killing low RPM performance.
https://www.summitracing.com/parts/sum-k1101

Be sure to read everything you can on breaking in a flat tappet cam!

As moderate as it is, a 204/214 cam would be a bit big in a 305 with tall gears, like 2.56 or 2.73.

Edit: Yes, if you install a new cam, you must use new lifters and probably will need a new timing set.

05-31-2020, 12:33 PM	#1
Bridgeman57 Registered User Join Date: Nov 2018 Location: Yuba city, California Posts: 86	1986 block, 1987 heads- CAM HELP I bough an engine with TBI and I’ve swapped it to carb. I want to put in a new camshaft but not sure what all I should replace because the cam in the block is setup for TBI. Because the degree would be off center a little. Would the stock cam be alright? And if I do add a cam, would I have to install new lifters, rods, valve springs, timing chain? Or would simply moving the cam timing a few degree be easier then spending roughly $500 more into a ****ty stock engine. Or just leave the cam alone and run it? Suggestions and advice would be great. Thanks

06-01-2020, 04:55 PM	#2
THI Active Member Join Date: Jan 2017 Location: Traverse City, MI Posts: 194	Re: 1986 block, 1987 heads- CAM HELP The stock TBI cam is really small - around 179* intake duration @ .050" lift. The old 193* intake/202* exhaust cam used in the 307-400 small blocks is a big improvement and would work with the valve springs. The TBI heads are poor flowing heads so going too big on a cam would not work well. Many have had good luck with an RV cam (204/214)

06-10-2020, 08:49 PM	#3
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,597	Re: 1986 block, 1987 heads- CAM HELP No reason the TBI cam won't work with a carb. But as mentioned above, it's quite small with an emphasis on low RPM torque. Something like a Summit Racing SUM-K1101 cam & kit would be an improvement, without killing low RPM performance. https://www.summitracing.com/parts/sum-k1101 Be sure to read everything you can on breaking in a flat tappet cam! As moderate as it is, a 204/214 cam would be a bit big in a 305 with tall gears, like 2.56 or 2.73. Edit: Yes, if you install a new cam, you must use new lifters and probably will need a new timing set. __________________ Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then! Last edited by MikeB; 06-11-2020 at 03:29 AM.



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